Addition and Subtraction
16 - 8 = ?
8
9 + ___ = 10
1
What comes next? What is the pattern?
1 + 4 = 5
2 + 5 = 7
3 + 6 = 9
_ + _ = _
4 + 7 = 11
3, 3, 6
3 + 3 = 6
3 + 3 = 6
6 - 3 = 3
6 - 3 = 3
The second grade classes have ant farms. Mr.Rather's class has 10 ants. Mrs. Lee's class has 10 ants. How many ants to both classes have altogether?
Both classes have 20 ants.
12 + 5 = ?
17
15 + ____ = 20
5
1 + 2 = 3
1 + 3 = 4
1 + 4 = 5
_ + + = _
1 + 5 = 6
6, 4, 10
6 + 4 = 10
4 + 6 = 10
10 - 4 = 6
10 - 6 = 4
Vicki has 17 red stickers and 9 blue stickers. How many more red stickers than blue stickers does she have?
Vicki has 8 more red stickers.
Double 8. Add one.
17
___ + 9 = 13
4
16 - 9 = 7
15 - 8 = 7
14 - 7 = 7
__ - __ = __
13 - 6 = 7
14, 6, 8
8 + 6 = 14
6 + 8 = 14
14 - 8 = 6
14 - 6 = 8
Mac has 4 cats. He also has 4 fish and 1 dog. How many pets does Mac have?
Mac has 9 pets.
Double 4. Subtract 1.
7
If ____ is added to 7, the answer will be 16.
9
14 - 3 = 11
13 - 4 = 9
12 - 5 = 7
__ - __ = __
11 - 6 = 5
5, 11, 6
6 + 5 = 11
11 - 6 = 5
11 - 5 = 6
Dale is in line at the zoo. 6 children are in front of him. 2 children are behind him. How many children are in the line?
9 children are in line
5 + 9 + 1 = ?
15
12
6 + 6 = 12
8 + 8 = 16
10 + 10 = 20
__ + __ = __
12 + 12 = 24
20, 14, 6
14 + 6 = 20
6 + 14 = 20
20 - 14 = 6
20 - 6 = 14
11 cents