Respuesta :

This is prime factorization
we need to know what number might go into 63
Most people who know their times tables remember that 9 * 7 = 63
7 is a prime number so it would go into the circle, and the 9 will go into the box

9 isn't prime, but 3 * 3 = 9.  3 is a prime number so the 3's will go into the circles below the 9.

If you need a final answer you can write 63 = 3 * 3 * 7

You can get the same factors if you use 3 *21 instead of 9*7 at the beginning.  I'll let you figure out that one.