problem
Favourite
Diagonal Sums
In this 100 square, look at the green square which contains the numbers 2, 3, 12 and 13. What is the sum of the numbers that are diagonally opposite each other? What do you notice?
problem
Favourite
Different Deductions
There are lots of different methods to find out what the shapes are worth - how many can you find?
problem
Favourite
Two and Two
How many solutions can you find to this sum? Each of the different letters stands for a different number.