Number Addition and subtraction

Transcription

1 Number Addition and subtraction This activity can be adapted for many of the addition and subtraction objectives by varying the questions used 1 Slide 1 (per class); number fan (per child); two different coloured whiteboard pens (per class/group) This activity can be adapted for many of the addition and subtraction objectives by varying the questions used. 2 Slide 2 (per class); 1 6 dice (per class/ group); 0 9 number fan or mini whiteboard, pen and eraser (per pair/ child) Busy bees Children play this game in two teams with the teacher as the quizmaster. Display: Slide 1. Each team must help their bees get home from a flower to their hive. One team plays across the board from left to right and the other team plays down the board from top to bottom. The left to right team goes first and asks the quizmaster for a question. All children in that team work out the answer and show it using their number fans. If more than three quarters (or other appropriate proportion) of the team answer it correctly, they draw a circle (bee) on one of the white hexagons in the first column. If less than three quarters of the team answer it correctly no circle (bee) is placed and it is the other team s turn. The top to bottom team then ask the quizmaster for a question. If three quarters of them answer it correctly, they draw a circle (bee) on one of the white hexagons in the first column. If less than three quarters of them answer it correctly no circle (bee) is placed and it is the other team s turn. Play continues with each player making a path to reach the opposite side of the board and their bees hive. The winner is the player whose bees reach their hive on the opposite side first. Snakes and ladders Split the class into two teams and give each pair/child a 0 9 number fan or mini whiteboard, pen and eraser. Display the snakes and ladders board on Slide 2. The teams take turns to answer a question given by the teacher. If more than three quarters of the children in a team give the correct answer, they roll the dice and move their counter that number of places along the snakes and ladders board (by drawing a coloured circle at their new position). If they land on a ladder, they climb up it and place their counter at the top of it. If they land on a snake, they slide down it and place their counter at the bottom of it. The winner is the first group to reach the finish. 38

2 Loop cards This activity can be adapted for many of the addition and subtraction objectives by varying the questions used Resource 31: Blank loop cards (per class/group) Explain that the children are going to play a game using loop cards and share the following information: 1 Each card has an answer to one question on the left ( I have ) and a different question on the right ( Who has? ). 2 Each child (or pair) will be given a card. 3 One child will be chosen to start the game and should stand up. 4 When the teacher says Go the starting child/pair read out their Who has? question on the right of the card (but not the answer on the left!). 5 All children work out the answer to the question and stand up if the answer is their I have number on the left of their card. The previous child/pair sit(s) down. 6 The new child/pair standing up then read(s) out the I have answer followed by the Who has question on their card. 7 Steps 5 and 6 are then repeated until the answer is reached on the card that was used to start the game. Give out the loop cards (all cards must be used so some children may need to have two). Say: I m going to time how long it takes you to answer all of the questions. Emphasise that it is important for everyone to speak loudly and clearly when it is their turn so that everyone else can hear. Ask the first child to read out their question and start timing. Offer help along the way by repeating each question and providing help to calculate the answer if it proves difficult. Some children may need to be prompted that they have the answer on their card. Record the time taken to complete the loop cards and repeat if time allows, challenging the children to beat their previous time. The activity can then be revisited at any time in a bid to beat the class s best time! Children can create their own set of loop cards to match a particular objective. Remind them that the answer on one card must be the answer to the question on the previous card. The question on the last card must have its answer on the first card. Addition/subtraction bingo This activity can be adapted for many of the addition and subtraction objectives by varying the questions used Resource 31: Blank loop cards (per class/group) Give each child a blank bingo card. Say the numbers 3 18 in order, one at a time, and ask the children to clearly write each number in one of the empty squares. Explain that you are going to say addition and/or subtraction calculations (with answers between 3 and 18). Tell the children that they must then work out each answer and tick it off on their bingo card. The first player to correctly tick off four numbers in a row is the winner! To enable easy checking of children s bingo cards, keep a note of the questions asked, in order. Allow the children to work in pairs. Children work in a smaller group with the questions being given more quickly. 39

3 Up to 20 Recall and use addition and/or subtraction facts to 20 Resource 150: Bingo cards (per child) For addition, remember that the circled numbers must total 20 or less. Write the numbers 1 to 20 on the whiteboard and explain to the children that you will circle two of them. The children should then add or subtract the two numbers and show the answer as quickly as possible using their number fans. Erase the circles and repeat for two different circled numbers. Make the answer Recall addition and/or subtraction facts involving multiples of 10 (per class); mini whiteboard, pen and eraser (per pair/child) Display: the, click Set up and select Random (10 99) for the Type of numbers. Give each pair or child a mini whiteboard, pen and eraser. Drag the first number card onto the screen and challenge the children to find as many addition and/or subtraction calculations as possible with that answer. Explain that all calculations must involve the addition or subtraction of a multiple of 10 to or from another two-digit number. Give children an appropriate amount of time for each number and invite them to share their answers. Write a list of their suggested calculations on the board. Drag the number card to the bin and repeat for the next two-digit number card. Choose two-digit numbers at random and write them on the board rather than using the Number cards tool. This activity could be adapted for other addition and subtraction objectives. one-digit number to/ from a multiple of 10 Resource 151: Multiples of 10 cards (per class); 1 9 number cards (per class/group); two or three small bags or boxes (per class/group); 0 9 number fan (per child) Pick two numbers Cut out the Multiples of 10 cards and put them in a small bag or box. Put the 1 9 number cards in a second small bag or box. Pass each bag/box to a different child and ask them to pick one card each. They should read out the numbers and then replace the cards in the bags/boxes from which they were taken. Write the calculation on the board and invite the children to show their answers using their number fans. The bags/boxes should be passed to other children and the activity repeated. For an activity involving addition and subtraction, cut out and put the addition and subtraction symbols in a third small bag or box. Ask another child to choose one of the cards. 40

4 Hidden cards one-digit number to/ from a multiple of 10 (per class); one 0 9 dice (per class/group); number fan (per child); six-sided dice with three sides labelled + and three sides labelled (optional) (per class/ group) Display: open the, click Set up and select Custom for the Type of numbers. Type 10 in both the First value and Increment boxes. Drag the cards numbered 10, onto the screen and arrange them randomly to mix them up. Click Hide all values to hide the numbers. (Do not include the 100 card if the children will be adding.) The children take turns to click the arrow on a number card to turn it over and roll the dice to generate a one-digit number. The two numbers are then used to create an addition or subtraction calculation. The children then use their number fans to show their answers. A point is scored for every correct answer. The winner is the child with the most points when all of the multiples of 10 cards have been used. The game can be extended by turning over and muddling the multiples of 10 cards on screen. To practise both addition and subtraction in this activity, children should use the specially labelled six-sided dice. The dice should be rolled to determine whether the calculation will be addition or subtraction. Rolling race two-digit number and ones mini whiteboard, pen and eraser (per child); one 0 9 dice (per pair) Addition Players take turns to roll a 0 9 dice. (If a 0 is rolled the player should roll the dice again.) Player 1 rolls the dice and writes the total at the top of their whiteboard. Player 2 takes their turn. Player 1 rolls the dice again. This time they mentally add this total to their previous total and then write down their running total. Player 2 takes their turn. The winner is the first player to reach 100. Subtraction Both players write 100 at the top of their whiteboards. The rules are exactly the same as for addition, except that the dice score is subtracted rather than added. Children play individually, timing how quickly they can reach 0 or 100. Children roll two 0 6 dice and add the two numbers together before adding or subtracting the total amount. 41

5 Adding ones two-digit number and ones (per class); 0 9 dice (per class); 0 9 number fan (per child) Display: the, click Set up and select Random for the Type of numbers. Give each child a 0 9 number fan. Drag a card onto the screen and ask a child to roll the dice to generate a one-digit number. Write the one-digit number alongside the randomly generated two-digit number with an addition or subtraction symbol between the two numbers. Ask the children to work out the answer and show it using their number fans. Clear the screen, drag a new card into place and ask a different child to roll the dice. Invite children to choose the two-digit number for each question. Invite children to roll two extra 0 9 dice to create a two-digit number for each question. Show me the answer two-digit number and tens (per class); 1 6 dice (per class); 0 9 number fan (per child) Display: the, click Set up and select Random for the Type of numbers. Give each child a 0 9 number fan. Drag the first number card onto the screen and ask a child to roll the dice to generate the number of tens to be added or subtracted to or from the number card. Ask the child to tell the rest of the class the number of tens. If the two numbers would total more than 100 (addition) or make less than 0 (subtraction), ask the child to roll the dice again. Give children an appropriate amount of time for each calculation and invite them to show their answers using their number fans. Drag the number card to the bin and repeat for the next two-digit number card. Ask a different child to roll the dice to generate the multiple of 10 to be added or subtracted. If addition and subtraction are both included in the same activity, flip a coin to decide whether children should add or subtract each pair of numbers. 42

6 two-digit number and tens 3 4 Slides 3 4 (per class); mini whiteboard, pen and eraser (per child) near multiple of 10 to/ from a two-digit number 5 Slide 5 (per class); Resource 4: number square or preexisting number square (per pair/child); 0 9 number fan (per pair/child) near multiple of 10 to/ from a two-digit number 6 7 Slides 6 7 (per class); Resource 4: number square or pre-existing number square (per pair/child); 0 9 number fan (per pair/child) Three numbers Give each child a mini whiteboard, pen and eraser. Display: Slide 3 and explain that children should write number sentences that involve two numbers from the slide and a multiple of 10. The multiple of 10 must be added to or subtracted from one of the numbers from the slide. The other number from the slide should be the answer. For example, = 37. Use Slide 4, which provides a different set of two-digit numbers. Set time limits for individual questions or challenge children to find a given quantity of number sentences in a fixed amount of time. Pick a number Give each pair or child a number square and a number fan. Display: Slide 5 and ask a child to choose one of the four arrows (left, right, up or down), which will take them to a slide showing a near multiple of 10. Choose a two-digit number and write it on the board. The children add or subtract the near multiple of 10 to or from the two-digit number (using the number square to help, if needed) and display the answer using their number fans. Restart the slideshow. Invite another child to choose an arrow to take them to a different near multiple of 10 and write a different two-digit number on the board. Repeat the activity with these new numbers. Penguins and fish Give each pair or child a number square and a number fan. Display: Slide 6 and draw a line on the board from one penguin to one fish. For addition, the total should be kept to less than 100. The children add or subtract the near multiple of 10 to or from the other two-digit number, using their number square for support, if needed. They then show their answer on their number fans. Repeat for other penguin and fish combinations. Reuse fish or penguin numbers in more than one question if needed. Display: Slide 7 for further questions using different numbers. Replace the numbers with others for this objective or adapt for use with other objectives. 43

7 Which two numbers? Add and/or subtract two two-digit numbers mini whiteboard, pen and eraser (per child) Write 12 two-digit numbers on the board in a 4 3 grid arrangement. For example, Circle two of the numbers and ask the children to add or subtract the numbers using their whiteboards to show you the answer (and for written/number line workings, if needed). Confirm the correct answer and cross off (or rub out) the two used numbers. Circle two new numbers and repeat until all 12 numbers have been used. Split the class into two teams. The team with the most children who give a correct answer to a question wins a point. The winning team is the one with the most points when all of the numbers have been used. Write more two-digit numbers on the whiteboard at the start of the game. Hop along Add and/or subtract two two-digit numbers (per class); Resource 4: number square or pre-existing number square (per pair); 0 9 number fan (per pair) Give each pair a number square to use for working out answers and a 0 9 number fan to show their answer. Remind/show the children how to use the number square to add/subtract one number to/from another by being rabbits and hopping/jumping along rows and up or down columns. Also remind the children to start with the larger number and add on the smaller number. Display: the, click Set up. Select 40 for the Number of cards and Random for the Type of numbers. Drag two of the cards onto the screen and ask the children to add or subtract the two numbers, as appropriate. Children work in pairs, using the number square for support, if needed, and then show their answer on their number fan. Drag two cards to the bin and drag two new cards onto the screen to repeat the activity. The class could be split into two teams (with the same number of pairs in each team) and every pair with the correct answer scores a point for their team. Choose pairs of numbers for the children to add and write them on the board rather than using the Number cards tool. Numbers can be chosen carefully to target different addition/subtraction techniques and other objectives can be covered. 44

8 Make that total Add three one-digit numbers 0 9 cards (per pair); mini whiteboard, pen and eraser (per pair) Give each pair a set of 0 9 cards. Ask the children to find three cards that total 12. Challenge them to find as many ways as possible to make 12 using three of the cards (there are 10). Choose a total from 10 to 17 and challenge children to find as many ways to make it as possible. Triple totals Add three one-digit numbers (per class); 0 9 number fan (per child) Display: the and click Set up. Select 40 for the Number of cards and Random 0 9 for the Type of numbers. Give each child a mini whiteboard, pen and eraser. Drag three cards onto the screen and challenge the children to work out the total of all three. Invite them to share their answers using their number fans. Drag the cards to the bin and drag three new cards onto screen to repeat the activity. Replace one or two cards at a time, rather than all three, to create a new question. Doubles bingo Doubles to 20 Resource 150: Bingo cards (per child) Give each child a blank bingo card. Say the even numbers from 10 to 40 in order, one at a time, and ask the children to clearly write each number in one of the empty squares. Explain that you are going to say a number between 5 and 20. Tell the children that they must double the number and tick it off on their bingo card. The first player to correctly tick off four numbers in a row is the winner! To enable easy checking of children s bingo cards, keep a note of the questions asked, in order. Allow the children to work in pairs. Children work in a smaller group with the questions being given more quickly. 45

9 Doubles to 20 8 Slide 8 (per class); 0 9 number fan (per child) Solve missing number problems involving addition and/or subtraction 9 48 Slides 9 48 (per class) Solve missing number problems involving addition and/or subtraction small piece of paper (per child); 0 9 number fan (per child) Double trouble Give each child a number fan. Display: Slide 8 and ask the children to show the answer to double 1 on their number fans. Ask a child to choose one of the arrows (up, down, left or right), which will take them to a slide showing a different number. Repeat the doubling activity and continue in the same way. Set a time limit for finding each double. Fastest finger first Divide the class into two teams and invite one child from each team (of similar ability) to the board and explain that you will show them a missing number calculation and lots of possible answers. They must work out the missing number and be the first to point to the number on the board to win a point for their team. Display: Slides Invite another child from each team to the board and reveal the question on Slide 10, and so on. Keep a note of the points scored by each team. The winning team is the one with the most points at the end of the game. This activity could be adapted to cover other addition and subtraction objectives by asking different questions. Write a question Write some example missing number addition and/or subtraction problems on the whiteboard. The examples should show the missing number and equals symbol in different positions, e.g = 17, + 4 = 17, =, = , 17 = + 4, 17 = Give each child a small piece of paper and a pencil. Ask them to write an addition or subtraction number sentence, as appropriate, where the total is 20 or less (addition) or where the number to be subtracted from is 20 or less (subtraction). They then draw a box around the number they would like to be the missing number. Collect the pieces of paper and give each child a 0 9 number fan. One at a time, write the children s missing number problems (leaving the box empty to indicate a missing number, e.g. 6 + = 15) on the whiteboard and challenge all children to work out the missing number. They display their answers using their number fans. 46

10 Addition and/or subtraction involving money Money tool (per class); small selection of classroom objects labelled with prices between 1p and 50p (per class/group); mini whiteboard, pen and eraser (per pair/child) Addition and/or subtraction involving money 49 Slide 49 (per class); mini whiteboard, pen and eraser (per child) Solve addition and subtraction word problems using mental methods Slides (per class); mini whiteboard, pen and eraser (per child) Classroom shopping Give each pair or child a mini whiteboard, pen and eraser. For addition, invite a child to choose two of the classroom objects and tell the rest of the class the prices. All children calculate the total cost of the two items and write the total amount on their whiteboards. For subtraction, invite a child to choose one classroom object and tell the rest of the class the price. Display: the Money tool and ask another child to drag a coin onto the screen to pay for the object. All children calculate the amount of change that should be given and write the amount on their whiteboards. For addition and subtraction, invite a child to choose two objects, allow time for all children to calculate the total cost and then invite a second child to drag a coin onto the screen to pay for the object. All children then calculate the amount of change. Children show both answers on their whiteboards. Use prices in pounds from 1 to 50 rather than pence. Object prices could be increased up to 99p or 99 for a subtraction only activity. Cafe menu Give each child a mini whiteboard, pen and eraser. Display: Slide 49 and point out the list of food and prices on the left and the list of drinks and prices on the right. For addition, say a total price and ask the children to work out which one food item and one drink item can be bought for that price. For example, a total price of 43p would buy one biscuit costing 8p and one cup of tea costing 35p OR one piece of cake costing 34p and one cup of squash costing 9p. For subtraction, say the name of one item and what coin a person uses to pay for it. Ask the children to work out how much change the person should receive. Alternatively, ask children to work out how much cheaper/more expensive one item is than another. For addition and subtraction, use a combination of the addition and subtraction activities. Lucky dip Give each child a mini whiteboard, pen and eraser. Display: Slide 50. Invite a child to choose and click on a question. All children then use their preferred method to work out the answer. Return to Slide 50 and invite a different child to choose another question. Work through as many of the nine questions as possible. Alter numbers used in the questions to create other versions of the resource. 47