Year 1

We can work out the difference between two two-digit numbers.

Year 1 Unit 14

What we are learning:

The language ‘subtraction’, ‘finding the difference’ and ‘taking away’ are all necessary for children to understand

It is good to do this practically with objects to compare the two amounts.
Then this can be represented on a number line so that you have the practical and the representation alongside each other.

Children can find the difference by using a number line, starting at the first (smaller) number and counting the number of places to reach the second (larger) number.

They can also start at the larger number and count back to the smaller one

ACTIVITY 1: USING EQUIPMENT FOR SUBTRACTION

ACTIVITY 2: EXPLORING THE LINKS BETWEEN ADDITION AND SUBTRACTION

Activities you can do at home:

Use a coat hanger with pegs on it. There are 15 pegs on the coat hanger, you can see 11. The rest are under a cloth.
How many are hidden under the cloth?
What number sentences could we write?
15 – ? = 11 11 + ? = 15 ? + 11 = 15 15 –11 = ?

How could we show this on a number line? Do this with different numbers.

Put 18 bears/biscuits/sweets in a box. Take out 10.
What number sentences could we write?
How many are there in the box now?
How could we show this on a number line?
How could we use a number square?

Good questions to ask:

How many more orange ones do you have?

How many less red ones do you have?

What is the difference between the two numbers?

If your child:

Is finding it difficult to understand what ‘finding the difference’ means
Set out two sets of practical objects in matched rows so that your child can see that there is a difference between them and count it
Is finding this easy
Use larger numbers up to 99 or ask them to count the difference in their head