Year 4

We can work out sums and differences of multiples of 100 or 1000

Year 4 Unit 3

What we are learning:

• ‘Sum’ is a different (mathematical) way of saying ‘the total found by adding’.
• ‘Difference’ is a different (mathematical) way of saying ‘the value between the two numbers’ which is found by subtracting the lower value from the higher value.
• Multiples of 10 have 0 units. 10, 20, 30, 40 ….
• Multiples of 100 have 0 tens and 0 units. 100, 200, 300, 400 …
•  Multiples of 1000 have 0 hundreds, 0 tens and 0 units. 1000, 2000, 3000, 4000 …
• Calculating sums and differences of multiples of 100 and 1000 can seem scary – just because of the size of the numbers involved.

ACTIVITY 1: ADDING MULTIPLES OF 100 AND 1000

ACTIVITY 2: HUNDREDS AND THOUSANDS

Activities you can do at home:

Practice speedy mental recall of addition and subtraction (one-digit numbers) i.e. 3+4 = 7, 9-2=7, 5+4=9, 7-2=5. Now make links to multiples of 100.

Say, If 3 add 4 equals 7, what will 3 hundreds add 4 hundreds equal?
Make similar links between subtraction of one-digit number and multiples of 100.
Extend this practice to multiples of 1000 when your child is ready.

Use a cut out set of question cards “Hundreds and Thousands”. Ask your child to sort the questions by looking for addition and subtraction patterns. Ask your child to explain the patterns they see.

Good questions to ask:

Can you count up/backwards in multiples of 10/100/1000 from….?
If 4 add 7 is 11 what is 400 add 700? What is 4000 add 7000?

If your child:

Is slow to work out answers because their knowledge of number bonds is insecure
Practice speedy mental recall of addition and subtraction (one-digit numbers). Time spent on this skill is a good investment as it makes all further maths easier and faster