WALT: use a rounding and compensating strategy to solve addition and subtraction problems.
eg.
+1
72-49=
72-50=22
22+1=23
Start here! (Please show your working!)
+2
1. 63-38= 25
63-40=23
23+2=25✓
+2
2.74-28=
74-30=44
44+2=46✓
+1
3.92-49=43
92-50=42
42+1=43✓
+1
4.75-39=36
75-40=35
35+1=36✓
+2
5.133-68=
133-70=63
63+2=65✓
+3
6.154-77=
154-80=74
74+3=77✓
+1
7.166-59= 104
166-60=106
106+1=107✓
+2
8.132-68=64
132-70= 62
62+2=64
+1
9.141-99=
141-100=41
41+1=42
+3
10.123-87=
123-90=33
33+3=36
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