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.
2
34 57 83 + 26
200
Review Combinations of Ten
•1 + •8 + •2 + •4 + •9 +
9 2 8 6 1
= 10 = 10 = 10 = 10 =10
5+ 7+ 6+ 3+
5 3 4 7
= 10 = 10 = 10 = 10
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
218