Step 1 Objective
Add and subtract mentally a 'near multiple of 10' to or from a two-digit number.
- Examples of what pupils should
know and be able to do - Probing questions
- What if pupils find
this a barrier?
Probing questions
Can you explain to me an efficient method for adding 19?
Why is this a good mental method for adding 19? What is the difference between adding 19 and subtracting 19 using this method? Show me why this is, using a 1-100 grid.