1.
Use models to write an expression and a number sentence. Then solve.
A secretary made 12 photocopies. Then she made 4 more. How many photocopies did she make in all?
A.
12 − 4; 12 − 4 = 8
B.
12 + 4; 12 + 4 = 18
C.
4 + 8; 4 + 8 = 12
D.
12 + 4; 12 + 4 = 16
Hint
2.
The + symbol makes which statement true?
A.
18 ___ 9 = 9
B.
8 ___ 4 = 12
C.
15 = 20 ___ 5
D.
1 + 7 = 16 ___ 8
Hint
3.
The − symbol makes which statement true?
A.
16 ___ 6 = 7 − 3
B.
50 ___ 12 = 64 − 2
C.
27 ___ 3 = 24
D.
6 + 11 = 10 ___ 7
Hint
4.
The − symbol makes which statement true?
A.
3 + 6 = 4 ___ 5
B.
8 = 14 ___ 6
C.
4 ___ 8 = 21 − 9
D.
12 ___ 5 = 17
Hint
5.
Use counters to show whether + or − makes the number sentence 8 ___ 6 = 2 true. Explain.
A.
+; 2 counters + 6 counters = 8 counters altogether.
B.
+; 6 counters + 2 counters = 8 counters altogether.
C.
−; 6 counters − 8 counters = 2 counters left.
D.
−; 8 counters − 6 counters = 2 counters left.
Hint