625 is a square number because it is 25 times 25 (a number times itself). Find two square numbers, each of which uses all three digits 1, 9 and 6.
ANSWER: 169 and 961 169 and 196 961 and 196 169 = 13^2, 196 = 14^2 961 = 31^2
13 * 13 14*14
169 =13 ^2 196 = 14^2
Arrange all the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 to give four different square numbers. (You make a square number when you multiply something by itself, so 49 is square because it is 7 times 7)
There are four solutions.