You may also like

problem icon

Prompt Cards

These two group activities use mathematical reasoning - one is numerical, one geometric.

problem icon

Consecutive Numbers

An investigation involving adding and subtracting sets of consecutive numbers. Lots to find out, lots to explore.

problem icon

Exploring Wild & Wonderful Number Patterns

EWWNP means Exploring Wild and Wonderful Number Patterns Created by Yourself! Investigate what happens if we create number patterns using some simple rules.

Adding Plus

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

How about trying to make $90$ using the digits $1-8$ and leaving the $9$ for adding on at the end?
A good place to start may be to push the $1$ and $2$ together to make $12$. What will you still need to add onto $12$ to make $90$?
Can you make $90$ simply by adding the remaining digits together? What could you do?
Perhaps you could try pushing the $2$ and $3$ together to make $23$? What do you need this time to make $90$?