Addition
10+5
10+5=15
Count by 2's to 12
2, 4, 6, 8, 10, 12.
15-5
15-5=10
12+4
12+4=16
Count by 10's to 90
10, 20, 30, 40, 50, 60, 70, 80, 90
16-4
16-4=12
11+7
11+7=18
Count by 5's to 50.
5, 10, 15, 20, 25, 30, 35, 40, 45, 50
17-4
17-4=13
15+4
15+4=19
Count by 10's to 120
10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120
20-6
20-6=14
13+7
13+7=20
Count by 5's to 100
5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100
20-12
There are 15 fish. 7 have big fins. How many fish have small fins?
8 fish have small fins.