The benefit of the worksheet is that the questions keep to fairly small numbers but increase in difficulty and can show clearly whether children have fully grasped the standard method or whether they need more practice.
The last three questions aer especially tricky and if children are getting these correct it would suggest that they have really understood the concepts.
If these are set as homework make it very clear that all working out needs to be shown (e.g. hundreds crossed out and made one smaller and adjusting 10 tens etc). Of course I see no reason why children should not use a calculator to see if they are correct and if incorrect to try and work out where they have gone wrong.
- © 2009 Maths Blog