During Maths this week, the children have been learning to count on to solve subtraction equations. They all know that addition is the inverse of subtraction and therefore the number sentence can be manipulated to help us. They also understand that it is easier to count forwards than it is to count backwards! The children have had to look at their subtraction sum and then work out what the addition would be, using a question mark to denote where their answer will go e.g. 567 - 234 = ? changes to 234 + ? = 567. This then enables them to see which number goes at the start of the number line and which goes at the end. The next part of the process is counting on in steps. The children have been encouraged to find the next ‘friendly’ number, usually the nearest ten and then count on in ‘friendly’ jumps until they reach their target number. Once all the jumps have been made all that remains is for them to be added together to give the final answer.
The children have been given some homework that will involve them following this process. If you could get them to be the ‘teacher’ and tell you how it is done it will really help reinforce their understanding.
If you have any questions about how to help your child with this method please come and ask a member of the year 3 team.