Back to Back Metre Sticks

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Cordelia Johnston
6 years ago
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What s this one all about? One of the sets of facts that you need to learn to be good at number work, is the number pairs that add to make 100.

1 What s this one all about? One of the sets of facts that you need to learn to be good at number work, is the number pairs that add to make , etc are easy because they are simply an extension of the tens facts and etc. But is not so easy. (Children will often think it should be because = 10.) But if you put two metre sticks back to back, magic happens! This activity also helps with finding change from 1. The teacher bits Learning Intentions: I know the multiples of ten that add to 100 and can find change from 1 for multiples of 10p. I know the multiples of 5 that add to 100 and can find change from 1 for multiples of 5p. I can find change from 1 for any amount. Ages: 6-8 What you need: Metre sticks with the 10s and 5s marked. A counting stick. The activities Introduction Gather the children on the carpet and show them a metre stick marked in 10s and 5s. Tell them that they are going to learn about money using a metre stick!

2 Play a show me game with them, pointing to the different tens numbers and getting them to say the numbers in chorus, eg: 20, 70, 30, 80, 10, etc. Replace the metre stick with a counting stick (with marks at the tens but no numbers) and play the game again. (See The Counting Stick for ways to develop this.) Number Pairs for 1 Once you are confident that pupils have a good sense of where the tens numbers are on the counting stick, put your finger at the mid point and ask them what length of stick is on each side of the finger. Establish that the stick is split in half so each side is 50. Now put the finger at one of the other marks, eg 80, and ask the same question. (80 on one side, 20 on the other) Repeat for several other numbers (eg , ). Establish through discussion that these number pairs all add to make 100 because the stick is 100cm long. Make the link with money. If something costs 90p you get 10p change from 1 etc. Play the metre stick game again, but this time you say the number you are pointing at on the stick and the pupils have to shout the number that would need to be added to make 1. (eg You point at 60, you say 60 and they shout 40.) Start with 50. Then move on to and (Show them how 60 is next to 50 so the partner number is also next to 50.) Finally do and The Story of 100 Build up a list of the number facts on the white board: = 100 AND/OR 1 + 0p = = p + 10p = = 100 etc 80p + 20p = 1 While the numbers are visible, play a chorus and response game, where you call out one number from a pair and the pupils call another. (You can combine this with a clapping rap - see Thigh, Clap, Snap, Snap.) Every so often, rub out one of the numbers and then continue the game using both the visible and the invisible numbers. Continue until all the numbers are rubbed out. 2

3 Take two metre sticks. Turn one upside down and lay it along the top of the other one. Let the pupils delight in the discovery that the number pairs are now together. Play the rap game again. Pair Work If you have enough metre sticks in the school, raid them all so you have one for each child! Pair the children up with two sticks each and let them play the game, taking in turns to call one of the numbers. (If you don t have enough, you can set this up as a group activity as part of a rotation.) Development: Multiples of 5 Once the pupils have rapid recall of the tens pairs, ask them to explore the in between numbers. What number is paired with 75? What is the partner for 45? Etc. Repeat the various activities with these numbers. Engage the pupils in discussion regarding the fact that the tens number for the partner number is one less than you expect. (75 is paired with 25 not 35.) Discuss why this is the extra ten comes from the two fives. Further Extension: Any Numbers When pupils are secure with this, they can graduate to finding the partner for any number on the stick (and hence the change for any amount from 1. There is now an additional challenge because the in-between numbers are not actually marked. 3

4 What you need Take two metre sticks and put them back to back like this. How to play Level 1 One person calls a tens number. (eg 30) The other person has to call the partner number. (eg 70) Level 2 One person calls a number ending in 5. (eg 75) The other person has to call the partner number. (eg 25) Level 3 One person calls any number on the stick. (eg 68) The other person has to call the partner number. (eg 32) 4

5 Finding Change What you need Take two metre sticks and put them back to back like this. How to play Level 1 One person calls an amount of money on the stick ending in 0 (eg 30p) The other person has to call the partner number. (eg 70p) Level 2 One person calls an amount on the stick ending in 5. (eg 75p) The other person has to call the partner number. (eg 25p) Level 3 One person calls any amount on the stick. (eg 68p) The other person has to call the partner number. (eg 32p) 5

The Counting Caterpillar

The Counting Caterpillar What s this one all about? There are lots of activities out there for practising the multiplication tables. This activity, combined with its partner activity, Tap Say Turn, helps