multiplication
2x2
4
30+30
10+_ = 15
10+5+15
5-2
3
8+8
16
5x5
25
50+50
100
15+_=30
15+15=30
10-6
4
9+9
7x7
100+100
200
50-_=20
50-30=20
30-15
15
10+10
20
10x10
100
200+200
400
10+15=_
10+15=25
50-40
10
11+11
22
12x12
144
500+500
1,000
100-99=_
100-99=1
1,000-981
19
12+12
24