Can you find which shapes you need to put into the grid to make the
totals at the end of each row and the bottom of each column?
What happens when you add the digits of a number then multiply the result by 2 and you keep doing this? You could try for different numbers and different rules.
Can you order the digits from 1-3 to make a number which is divisible by 3 so when the last digit is removed it becomes a 2-figure number divisible by 2, and so on?
What do you know about division that might help?
Having a calculator to hand will be useful.
Have a look at each approach. What do you think he/she/they were doing?
How do you think that will help to solve the problem?
What do you think he/she/they would have done next?