WALT subtract using place value

67 - 42 = 25
35 - 12 = 23
78 - 32 = 46
56 - 21 = 35
86 - 21 = 65
42 - 11 = 31
79 - 54 = 25
65 - 43 = 22
59 - 31 = 28
33 - 21 = 65