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Slide 2 / 111 Kindergarten Operations & Algebraic Thinking: Part 2 2015-03-11 www.njctl.org
Slide 3 / 111 Part 2 Unit Topics Exploring Subtraction Word Problems Modeling Subtraction Equal Sign Connecting Cubes Click on the topic to go to that section Vertical Subtraction Number Facts to 5 Addition & Subtraction Games Addition & Subtraction Problem Solving
Slide 4 / 111 Subtraction Understand subtraction as taking apart and taking from. Provide children with opportunities to subtract items in their environment. Expose them to subtraction throughout the day by solving word problems that relate to life experiences. Decompose numbers less than 10 into pairs in more than one way. Fluently subtract within 5 by asking questions that foster sample subtraction (ex. There are 4 children at listening center. There are only 3 headphones. How many children should leave the center?)
Slide 5 / 111 Subtraction Reading Books Ten Little Mice by Joyce Dunbar. (Harcourt Brace & Co., 1990). Elevator Magic by Stuart J. Murphy. (Harper Collins, 2000). 10, 9, 8, by Molly Bang. (Harper Collins, 2000). Mmmm... Cookies! Simple Subtraction by Monica Weiss (Troll Associates,1992).
Slide 6 / 111 Exploring Subtraction Click to Return to Table of Contents
Slide 7 / 111 Let's Explore Subtraction Have the children act out the following problems. 1. There are three children playing with blocks. One moves to the drama center. How many are still playing with blocks? 2. Four children are jumping. Two stop! How many are still jumping? 3. There are five cookies on the plate. Tom and Sue each eat one. How many are left on the plate? 4. Pass out 6 paper plates. Now take 2 away. How many plates are on the table now? 5. Your teacher has 5 papers. There are 4 children at the table. She gives each child a paper. How many does she have left?
Slide 8 / 111 Exploring Subtraction Pull How many are left?
Slide 9 / 111 Exploring Subtraction Pull Fish Bucket How many are left?
Slide 10 / 111 Pocket Subtraction Pull
Slide 11 / 111 Exploring Subtraction Pull down a number of space ships. Move some away to show the number taking off. Write how many are left.
Slide 12 / 111 1 There are 4 birds on the line. If two fly away how many are left? A 1 B 2 C 3 D 4
Slide 13 / 111 2 There are 3 girls dancing. One has to go home. How many are left? A 0 B 1 C 2 D 3
Slide 14 / 111 3 There are 5 cars in the race. Two have to stop for gas. How many are still racing? A 1 B 2 C 3 D 4
Slide 15 / 111 4 There are 3 rocket ships. One blasts off. How many are still on the ground? A 0 B 1 C 2 D 3
Slide 16 / 111 Word Problems Click to Return to Table of Contents
Slide 17 / 111 Exploring Subtraction through Word Problems Have the children act out the stories. Tell and write the story. (Ex. There were 3 birds on the ground. One flew into a tree. How many are still on the ground?) Draw pictures to depict the number story. Then cross out the objects you take away. Write the number sentence to depict the story. 3-1=2 Using counters and drawing pictures, the children can create their own stories on a white board or paper.
Slide 18 / 111 Exploring Subtraction Pull
Slide 19 / 111 Exploring Subtraction
Slide 20 / 111 Exploring Subtraction Pull
Slide 21 / 111 Exploring Subtraction
Slide 22 / 111 Exploring Subtraction
Slide 23 / 111 Exploring Subtraction
Slide 24 / 111 5 There are five dolls at the store. The children buy three. How many are left at the store? Students should use counters. A 5 B 4 C 3 D 2
Slide 25 / 111 6 Mom put 4 apples in the basket. Three fell on the floor. How many are still in the basket? Students should use counters. A 4 B 3 C 2 D 1
Slide 26 / 111 7 The girl has 6 balloons. Two fly away. How many does she have now? A 6 B 5 C 4 D 2
Slide 27 / 111 8 There are 7 bunnies in the pen. Four are jumping out. How many will stay in the pen? A 3 B 4 C 5 D 6
Slide 28 / 111 Modeling Subtraction Click to Return to Table of Contents
Slide 29 / 111 Exploring Subtraction The teacher will make up a subtraction story and model on the board. The children will then model teacher's actions using stick and counters at seats. Pull Example there are four pebbles on the beach. The waves washes away two. How many are left?
Slide 30 / 111 Minus Symbol Pull Make up story to go with number of counters. Terminology- subtracting, minus, take away Eventually write a corresponding number model (3-2).
Slide 31 / 111 Minus Symbol
Slide 32 / 111 Minus Symbol
Slide 33 / 111 Pull Let's Subtract minus symbol Our Subtraction Problems
Slide 34 / 111 Let's Subtract minus symbol Our Subtraction Problems
Slide 35 / 111 Let's Subtract minus symbol Our Subtraction Problems
Slide 36 / 111 Concentration Problem (Next Page) Discuss that the equation must match the picture problem. Have the students draw their own pictures the first time through to represent the equation. Students can use as a center activity.
Slide 37 / 111 Concentration Problems Match the problem to the equation
Slide 38 / 111 Subtraction Shell Game Pull Player one. Player two. -2-1 0-3 -1 0-2 -1-3 0-2 -2-1 -3 The End -1-1 0
Slide 39 / 111 Disappearing Rabbit Be the first to move all bunnies from hat to fence. Pull
Slide 40 / 111 Disappearing Rabbit Be the first to move all bunnies from hat to fence. Pull Students need dice with -1, -2, 0, -1, -2, -3
Slide 41 / 111 9 Is this the subtraction symbol? Yes No
Slide 42 / 111 10 Which is the subtraction (minus) symbol? A B C
Slide 43 / 111 11 Do we take objects away when we subtract? Yes No
Slide 44 / 111 12 Which one shows minus 2? A + 2 B = 2 C - 2 D 2
Pull Slide 45 / 111 Understanding Subtraction Pull down dogs to represent first number. Move some over to second number to show how many are leaving. Write how many are left. 4 1 4 2 5 4
Slide 46 / 111 Pull Understanding Subtraction Write the numbers for problem.pull down dogs to represent first number. Move some over to second number to show how many are leaving. Write how many are left.
Slide 47 / 111 Understanding Subtraction Pull down counters for the first number. How many are bouncing away? (second number). Write how many are left. 5 2 6 3 5 1
Slide 48 / 111 Understanding Subtraction Create your problem. Pull down counters for the first number. How many are bouncing away? (second number). Write how many are left.
Slide 49 / 111 Equal Sign Click to Return to Table of Contents
Slide 50 / 111 Subtraction Equal Symbol = Pull Pull
Slide 51 / 111 Subtraction Equal Symbol = Pull Pull
Slide 52 / 111 Equal Symbol = Pull Pull
Slide 53 / 111 Equal Symbol = Pull Pull m
Slide 54 / 111 Equal Symbol = Pull Pull
Slide 55 / 111 Connecting Cubes Click to Return to Table of Contents
Slide 56 / 111 Connecting Cube Problems The children work at seats while demonstration takes place on board. Write the problem and then use the cubes to figure out the answer.
Slide 57 / 111 Connecting Cube Problems The children work at seats while demonstration takes place on board. Write the problem and then use the cubes to figure out the answer.
Slide 58 / 111 Connecting Cube Problems The children work at seats while demonstration takes place on board. Write the problem and then use the cubes to figure out the answer.
Slide 59 / 111 Subtracting Pattern What is it? 10-1 = 9-1 = 8-1 = 7-1 = 6-1 = 5-1 = 4-1 = 3-1 = 2-1 = 1-1 = Pull
Slide 60 / 111 13 Solve this problem. Use your counters. 4-1 = A 4 B 1 C 3 D 2 4-1 =
Slide 61 / 111 14 Solve this subtraction problem. Use your counters. 6-4 = A 4 B 3 C 2 D 1 6-4 =
Slide 62 / 111 15 Is the answer to this problem 3? Yes No 6-3 =
Slide 63 / 111 16 Is the answer to this subtraction problem 1? Yes No 3-3 =
Slide 64 / 111 17 What is the answer to this problem? Use your counters. 2-0 = A 2 B 4 C 0 D 1 2-0 =
Slide 65 / 111 Vertical Subtraction Click to Return to Table of Contents
Slide 66 / 111 Subtracting Down Pull 5-2 = 3 4-3 = 1 5-2 3 4-3 1
Slide 67 / 111 Subtracting Down Match the problems. 6-3 = 3 2-1 = 1 5-5 = 0 4-3 = 1 5-5 0 6-3 3 4-3 1 2-1 1
Slide 68 / 111 Complete the Problems Subtracting Down 8-5 Pull 3-1 5-4
Slide 69 / 111 Subtracting Down Pull
Slide 70 / 111 18 Are these the same problem? Yes No 2-1 = 1 2-1 1
Slide 71 / 111 19 Do they represent the same problem? Yes No 4-3 =1 4-1 3
Slide 72 / 111 20 Solve the problem. What is the answer? A 2 B 1 C 3 D 0 3-2
Slide 73 / 111 21 What is the answer to the problem? A 4 B 3 C 2 D 1 5-4
Slide 74 / 111 22 What is the answer to this problem? A 0 B 1 C 2 D 3 4-1
Slide 75 / 111 23 Is the answer to this problem 4? Yes No 4-0
Slide 76 / 111 Number Facts to 5 Click to Return to Table of Contents
Slide 77 / 111 Fluently Subtract The following pages provide fluency practice for subtraction within 5.
Slide 78 / 111 Can You Subtract? Pull click 5-2 3 click 3-1 2 click 1-0 1 click 5-1 4 click 2-0 2 click 2-1 1 click 4-2 2 click 4-1 3
5-2 3 Slide 79 / 111 Pull 5-1 4 4-2 2 3-3 0 2-1 1 5-0 5
Slide 80 / 111 And the answer is? Subtraction Facts
Slide 81 / 111 24 Do not use counters. What is the answer? A 1 B 2 C 3 D 4 4-0
Slide 82 / 111 25 Do not use counters. What is the answer? A 1 B 2 C 3 D 4 2-1
Slide 83 / 111 26 Do not use counters. What is the answer? A 1 B 2 C 3 D 4 4-1
Slide 84 / 111 27 Do not use counters. What is the answer? A 1 B 2 C 3 D 4 5-3
Slide 85 / 111 28 Do not use counters. What is the answer? A 1 B 2 C 3 D 4 3-1
Slide 86 / 111 Addition & Subtraction Games Click to Return to Table of Contents
Slide 87 / 111 Addition/Subtraction Games Demonstrate on the Interactive Whiteboard, then photocopy the game so the children can play at their tables with a partner. Besides the game board you will need dice marked with numbers and addition and subtraction symbols. This will reinforce the meaning of addition and subtraction symbols.
Slide 88 / 111 Kangaroo Number Line Talk about the number line. Discussion... we can move forward (+) We can move backward (-) Eventually write equation to go with throw. Need one die with +1, +2, +3, -1,-2, 0
Slide 89 / 111 Kangaroo Number Line Subtraction/Addition 0 1 2 3 4 5 6 7 8 9 10 Roll dice and move the kangaroo along the number line. Children can follow along with number lines and markers at seats.
Slide 90 / 111 Plus or Minus Game (reinforce the meaning of the addition and subtraction symbols) To Play: You need two game boards. Take turns rolling the cube. + number (add that number of counters to your board) - number (subtract that number from board *unless there are no counters on their board) 0 means no move Game ends when all squares are covered. As the children get more proficient... they can write a number sentence to record their moves. You can set up at math center or use as whole group (pairing with partners at tables). Game boards on next page.
Slide 91 / 111 Plus or Minus Game Player One Player Two
Slide 92 / 111 Addition- Subtraction Activities The following games can be set up as a math center or done as a whole group activity. Demonstrate on the board first with student participation. Then have students play with a partner using the game sheet at table.
Slide 93 / 111 Addition/Subtraction Candy Game Pull Team A Team B
Slide 94 / 111 Addition/Subtraction Dinosaur Race Game Pull
Slide 95 / 111 Addition/Subtraction Bumble Bee Game Pull
Slide 96 / 111 Addition/Subtraction Fairy Tale Game Pull H p f o +
Slide 97 / 111 Addition & Subtraction Problem Solving Click to Return to Table of Contents
Slide 98 / 111 Problem Solving Addition or Subtraction Talk about the pictures and what is happening. The children have to decide if this represents an addition or subtraction problem. Are we adding objects or taking some away. Do we use the + or - symbol? Then choose the correct problem.
Slide 99 / 111 Problem Solving Choosing the Operation Pull 5-2 3 5 +2 7
Slide 100 / 111 Problem Solving Choosing the Operation Pull 3-1 2 3 +1 4
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Slide 103 / 111 Problem Solving Choosing the Operation Pull
Slide 104 / 111 Create your own problem. Is this an addition or subtraction story? Do we use + or - symbol?
Slide 105 / 111 Create your own problem. Is this an addition or subtraction story? Do we use + or - symbol?
Slide 106 / 111 29 What problem matches the story? A 5-3=2 B 5+3=2 C 5+3=8 D 5-3=1 There are 5 apples. Joe eats 3. How many are left?
Slide 107 / 111 30 Bonnie finds 3 shells. Then she finds 2 more. How many does she have now? Do we add or subtract? A + B -
Slide 108 / 111 31 Dom had 4 cars. He loses one. How many does he have now? A + B -
Slide 109 / 111 32 Which equation matches the story problem? A 3+3=6 B 6-3=3 C 3+2=6 D 6-6=0 Ryan finds 3 frogs. Ethan finds 3 frogs. How many frogs do they have altogether?
Slide 110 / 111 33 Find the equation that matches the story problem. A 4+4=8 B 4+3=7 C 7-3=4 D 8-4=4 Justin shoots 7 basketballs. 3 go in the net. How many missed the net?
Slide 111 / 111 Let's Get the Beat of Subtraction