There are four addition calculations hidden below.
Your challenge is to put them in order, from easiest to hardest. Try to do this without actually calculating each answer if you can.
Click on 'Show' to see them.
42 + 47
42 + 18
42 + 39
42 + 3
How did you decide the order?
We would love to hear the reasons for your final order.
You might like to do exactly the same with the set of four subtraction calculations hidden below.
26 - 18
26 - 7
26 - 3
26 - 10
Create a set of four additions or four subtractions yourself, which you think could be put in order from easiest to hardest.
Give them to someone else to order.
Do they agree with your final order? Why or why not?
You may find it useful to print off this sheet, which contains the two sets of calculations. You could cut them up into two sets of four cards.