subtraction
300-20?
280
how many is 16 tens and 9 ones?
169
3x4?
12
5+17?
22
make 42
4 tens and 2 ones
3 tens and 12 ones
2 tens and 22 ones
1 ten and 32 ones
16-7?
9
how many tens in 145?
14
12x2?
24
120+11?
131
make 66
6 tens and 6 ones
5 tens and 16 ones
4 tens and 26 ones
3 tens and 36 ones2 tens and 46 ones
1 ten and 56 ones
25-12?
13
how many 10s in 330?
33
7x3?
21
13+17?
30
36-9?
27
how many 10s in 453?
45
4x4?
16
67+4?
71
101-11?
90
how many 10s in 765?
76
9x3?
27
45+15?
60