Year 2

We can round numbers to the nearest 10.

Year 2 Unit 15

What we are learning:

• Being able to round is an important skill and is used when estimating.
• There are rules about rounding which need to be followed. The rule for rounding numbers that are half way between two tens (numbers that end in a 5) is to round it up. So 35 rounded to the nearest 10 would be 40.
• When rounding to the nearest 10, the rounded value will always be a multiple of 10. (10, 20, 30, 40 ….)
• Always start by doing this practically, using a number line so that your child can see the number that is the nearest 10
• Continue to use a number line until your child can visualize it and can therefore do the rounding in their head.

ACTIVITY 1: ROUNDING TO THE NEAREST 10

Activities you can do at home:

Using a number line that is marked with the multiples of 10. Write the following numbers onto the number line 57, 28, 31, 72. Ask your child, Which of the tens numbers (multiples of 10) is 57 the closest to? Do the same with all the numbers.

You can also say, Tell me another number that is close to 60 or Tell me another number that is close to 70.

Ask, What about the number 25? Which tens number is 25 closest to? Establish that it is half way between the numbers and that we round these numbers up – it is a Mathematicians Rule

Try some other numbers ensuring that they include numbers that end in a 5.

Make a set of numbers cards for example 12, 67,35, 81, 94, 16, 65, 71, turn over each card one at a time ask your child to round the number to the nearest ten. See how quickly the child can do this. Then swap roles – the child turns over the cards and checks your answers. Make deliberate mistakes for the child to correct, but not too many mistakes. 

Good questions to ask:

Can you round this to the nearest 10?
What happens if the number we are rounding is exactly half way between two tens?

If your child:

Rounds number to the wrong 10, e.g. rounds up when they should round down
Use a number line to demonstrate where your number is in relation to the ten above