# Week 2 - 31.03.20

Subtraction

At this age children need to understand that when we subtract, we always take away the smallest number from the biggest number in an equation. The answer we end up with should always be smaller than the starting number because we have taken an amount away.

A good way to demonstrate this is to use a selection of small objects to create a starting number. You can then ask your son/daughter to count how many objects you have altogether (e.g. 10). Following this you can then ask them to subtract/take-away a certain amount (e.g. 4). You should then ask them how many objects they have left and whether this number is smaller or bigger than the original amount.

Once they have a good understanding of what Subtraction means they can then write ‘number sentences’ to record what they have just done practically e.g. 10 – 4 = 6.

You could also reverse this so that you provide your son/daughter with a ‘number sentence’ that they then need to find the answer for. They should hopefully follow the above process independently to work out the answer.

*Number tracks, number lines and hundred squares are helpful when working out answers without practical equipment. It is important that if you are using these resources that the children understand that we always jump to the left or backwards when we are working with Subtraction equations.

Activity 1

Practise counting backwards from any number between 10 and 100. If you’d like to go all the way from 100 why not try this video for a bit of fun…

Activity 2

Subtraction Squares - A game that can be played in pairs or with the whole family.

Draw out or print a grid of 3 by 3 squares and fill each square with any numbers between an agreed range e.g. 1-10 or 1-20 etc.

How to play.

1. One player will pick a number within the agreed range followed by a spin on the online wheel.

https://wordwall.net/resource/49009/maths/random-number-wheel-1-10

2. This will then give you the Subtraction ‘number sentence’ for the other player(s). For example, you pick the number 20 and then spin a 2 on the wheel.

This becomes 20 - 2.

3. Anyone with the answer to this equation can then cross it off their grid.

4. The next player will then repeat steps 1 and 2.

5. You will need to keep taking it in turns until a player has managed to cross off all their numbers in their grid. They are then the winner of the game!

Activity 3

Colouring Subtraction! Workout which colours you need by answering the Subtraction questions.

Activity 4

A choice of two activities to practise your Subtraction skills.

*Alternatively, you may want to make your own physical versions at home.

Interactive Number Line

https://apps.mathlearningcenter.org/number-line/ - Use the drawing tools (found on the bottom panel) to draw on your jumps.

Interactive Hundred Square

https://apps.mathlearningcenter.org/number-line/ - Using the colour blocks on the left you can jump on the numbers you need to subtract.

Remember that you start on the number you are subtracting from and then count the jumps as you do them/land.

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