you have to make it into a one variable equation
21 * 21 = 7 * 7 * X
441 = 49 * X
441/49 = X
9 = X
7 times 9 equals 63.
How about: 3 times -7 = -21
1 time 21; 3 times 7; 7 times 3; 21times 1
How about: 1*21 = 21 or 3*7 = 21
3 times 7...
7
3 x 7 = 21
3 x 7
7x3=21
9 times 7/3 = 21
3 divided by 21=7,so 3 times 7=21
3 times 7 equals 21.