Different Ways of Multiplying
Review
Memorizing Multiplication Tables for 1-digit multiplication plus 10s, 11s, 12s
Printable multiplication chart
Different Multiplication Techniques
Multiplication Techniques
- Standard
- Line Multiplication
- FOIL
- Approximate Values
- Area methods of multiplication
Why Learn Different Ways to Multiply?
Standard Multiplication
- Only one method to remember
- No decision to make on how to solve the problems
- Every arithmetic multiplication can be solved this way
Different Types of Multiplication
- One method might be faster or more accurate than the others
- Fun to chose which method works best
- Every arithmetic problem and algebra problems use these methods
- Sets the stage for understanding advanced math multiplication
FOIL
- Front, Outer, Inner, Last
- Remember Weird Al and Multiplication.
- 34 x 12
- = (30 + 4) x (10 + 2)
- Front:
- Outer:
- Inner:
- Last:
- Add together
Approximate Values
- A version of FOIL
- 34 is close to 35
- 12 is close to 10
- 34 x 12 = (35 -1) x (10 +2)
- Front:
- Outer:
- Inner:
- Last:
- Add:
- Good approximations
Multiplication Problems
Do these problems in at least two different ways.
Figure out which way works best
- 24 x 99 =
- 100 x 567 =
- 111 x 34 =
- 5 x 248 =