Addition shortcuts
- 2. 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
- 6. Review Combinations of Ten
•1 + 9 = 10 5+ 5 = 10
•8 + 2 = 10 7+ 3 = 10
•2 + 8 = 10 6+ 4 = 10
•4 + 6 = 10 3+ 7 = 10
•9 + 1 =10