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Learn useful shortcuts for quick and accurate addition in columns. Discover the commutative property and how to efficiently add numbers by looking for combinations of ten. Practice adding long columns and using multiplication for repeated numbers.
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Shortcuts in Addition By Monica Yuskaitis
Adding Long Columns • Since addition is Commutative it doesn’t matter which numbers you add first. 4 + 2 + 5 + 1 = 12 1 + 4 + 5 + 2 = 12
Adding Long Columns • Begin by looking for combinations of ten. 34 57 83 26 +
Adding Long Columns • Add up your ten combinations first. 2 34 57 83 26 + 0
Adding Long Columns • Add up your ten combinations again. 34 57 83 26 2 + 2 0 0
Review Combinations of Ten 9 5 • 1 + = 10 5 + = 10 • 8 + = 10 7 + = 10 • 2 + = 10 6 + = 10 • 4 + = 10 3 + = 10 • 9 + =10 2 3 8 4 6 7 1
Adding Long Columns • When a number keeps repeating use multiplication. 2 32 36 88 26 36 + 8
Adding Long Columns • When a number keeps repeating use multiplication. 2 32 36 88 26 36 + 2 1 8
