Page 9 - 2024 prim 4 SUMMERY_Neat
P. 9
Delta Modern Language Schools
Primary stage
Maths Department
Prim 4 2024-2025
Properties of subtraction
Ex.: 1024 - 0 ≠ 0 -1024
1) No identity A - 0 ≠ 0 - A ≠ A
We can’t change the place of
numbers
2) Not Ex.: 5 – 2 = 3 , 2 - 5 ≠ 3
Commutative
so, 5 - 2 ≠ 2 -5
A - B ≠ B - A
Solve what in the parentheses first.
We can start by any group
3) Not Ex.: ( 5 - 3 ) - 2 = 2 – 2 = 0
Associative = 5 – 1 = 4
SO, ( 5 - 3 ) - 2 ≠ 5 - ( 3 - 2 )
( A - B ) - C ≠A - ( B - C )
= B + ( A + C )
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