Page 10 - prim 4 كامل
P. 10
Delta Modern Language Schools
Maths Department
Prim 4 2023-2024
c) Compensate to make Benchmark number (Compensation)
Ex.1 : 199 + 52 = ..251..
+1
200 + 52 = 252 - 1 251
d) Break up and bridge : 63 = 60 + 3
Ex.1 : 63 + 29 ++
29 = 20 + 9
Ex.2 : 489 – 134 80 + 12 = 92
489 = 400 + 80 + 9
- --
134 = 100 + 30 + 4
300 + 50 + 5 = 355
e) Add to subtract :
(Add to subtrahend till it equals the minuend to get the difference)
Ex.1 : (Minuend) 92 – 67 (Subtrahend)
67 + 3 = 70
70 + 2 = 72
72 + 20 = 92
,So the difference = 3 + 2 + 20 = 25
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