subtraction
21-13=?
8
59+24=?
83
20 divided by 5 = ?
4
what's my rule ? 1,2,4,8,16,32,_
64
39-17=?
22
57+29=?
86
16 divided by 4=?
4
what's my rule ? 2,500 , 5,000 , 7,500 _____
10,000
47-31=?
16
57+34=?
91
100 divided by 10=?
10
what's my rule ? 25,50,75,100,125___
150
89-53=?
36
345+178=?
523
25 divided by 5=?
5
what's my rule ? 500,452,404,___
356
196-57=?
139
978+789=?
1,767
100 divided by 50=?
2
what's my rule 1,6,16,36,__
72