Year 3

FREE maths resources for all

Year 3 Menu

We can explain how we add and subtract numbers in our heads.
We can explain how to put three–digit numbers in order.

Year 3 Unit 5

What we are learning:

  • Children will learn how to give a clear and accurate explanation by hearing examples regularly. At appropriate times when playing maths games together try to provide an explanation as to how you worked out the answer. Ask, Would you have worked out the answer in the same way? and provide your child with the opportunity of explaining what they would have done. Try not to interrupt their explanation, but ask questions at the end if they missed out relevant details.
  • Some children (and adults) find it hard to explain – even when they have got the answer to a calculation right. Try asking for the explanation in a different way, If I was going to have a go at answering this question, what should I do first?… Then what should I do?
  • Sometimes children (and adults) do just know number facts i.e. 4 x 5=20. If your child says “I just knew it” when you ask them to explain how they did a calculation, consider whether it really is a fact they just know… and be quick to give praise if it is!

Activities you can do at home:

Cut up the sheet “Ordering 3-digit numbers” (an explanation broken down into individual sentences). Making sure that the order of the sentences is not sequenced correctly; give the sentences to your child.
They should read the sentences – with your help if needed, decide upon the correct sequence and use the explanation to sort the three-digit number cards provided. Discuss the ‘time connectives’ used (first, next,
finally) they help to order an explanation.

Using the 3-digit number cards provided in ‘Ordering three-digit numbers’ take it in turns to work out the digit sum of each number (the total if we add all of the digits together). The digit sum of 499 is 4+9+9=22. When it is your turn to work out the digit sum explain the order in which you add the 3 digits together – and why you chose that order!

Good questions to ask:

How did you work out the answer?
Could you have worked out the answer in another way?
Which way is easier / quickest?
What do you need to do first to answer this question?

If your child:

Finds it difficult to explain their method
Ask them to talk through what they are doing as they do it


Explaining our mental calculations PDF

Extension Activity

Please use this activity when you think your child understands the unit of work. It will deepen and extend your child’s understanding of this unit.


Extension activity (PDF)