You must choose four different digits from 1-9 and put one in each box. For example:
This gives four two-digit numbers:
| 52 | (reading along the 1st row) |
| 19 | (reading along the 2nd row) |
| 51 | (reading down the left hand column) |
| 29 | (reading down the right hand column) |
In this case their sum is 151.
Your challenge is to find four different digits that give four two-digit numbers which add to a total of 100.
How many ways can you find of doing it?
This problem is adapted from "Make 200" which appears in Mathematical Challenges for Able Pupils Key Stages 1 and 2, published by DfES. You can order copies on 0845 60 222 60 or via email: dfes@prolog.uk.com. Please quote code 0083/2000.