Put the missing symbol into the box to make these number sentences correct.

Use the symbols +,  −,  ×,  ÷ and  =.

17 ☐ 21 = 38

17 ☐ 3   = 51

57 ☐ 29 = 28

9   ☐ 63 ÷ 7

You can make most of the number sentences below correct by putting in […]