tricks to mastering multiplication facts
DESCRIPTION
Tricks to Mastering Multiplication Facts. Multiply by 2. Double a number Skip counting by 2’s MEMORIZE THESE!! Examples:2 X 4 = 2 + 2 = 4 5 x 2 = 5 + 5 = 10 2 x 8 = 8 + 8 = 16. Multiply by 10. When multiplying a number by 10, write the number down and - PowerPoint PPT PresentationTRANSCRIPT
TRIC
KS TO M
ASTERIN
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MULTIP
LICAT
ION FA
CTS
MULTIPLY BY 2
Double a number
Skip counting by 2’s
MEMORIZE THESE!!
Examples: 2 X 4 = 2 + 2 = 4
5 x 2 = 5 + 5 = 10
2 x 8 = 8 + 8 = 16
MULTIPLY BY 10
When multiplying a number by 10,
write the number down and
annex a zero to right of the one’s place
Examples: 7 x 10 = 70 10 x 8 = 80
30 x 10 = 300 14 x 10 = 140
MULTIPLY BY 11
For the number you are multiplying by 11 …
the product is that number written as a
double digit
Examples: 4 x 11 = 44 11 x 3 = 33
11 x 7 = 77 6 x 11 = 66
Exception: 11 x10 = 110
11 x 12 = 132
MULTIPLY BY 5
Remember: Any number times 5, ends in a 5 or 0
Use the analog clock,’s minute hand.
Each number on the clock represents 5 minutes
10 minutes past the hour, the minute hand is on the 2, so 5 x 2 = 10
25 minutes past the hour, the minute hand is on the 5, so 5 x 5 = 25
45 minutes past the hour, the minute hand is on the 9, so 5 x 9 = 45
60 minutes past the hour, the minute hand is on the 12, so 12 x 5 = 60
MULTIPLYING BY 9
The factor that you are multiplying by, drop by 1
9 x 3 = 2_ 9 x 5 = 4_
The two digits of the product should add up to 9
9 x 3 = 2_; since 2+7=9, the product is 27 => 9x3=27
9 x 5 = 4_; since 4+5=9, the product is 45 => 9x5=45
MULTIPLY BY 12We all know that 12 = 10 + 2
Multiply the factor that you are multiplying by 12
by 10
then multiply it by 2
then add them together
12 x 4 => 10 x 4 = 40
2 x 4 = 8; 40 + 8 = 48
12 x 4 = 48
This is just using the Distributive property of multiplication and addition
MULTIPLY BY 4’S
Double the 2’s
If I don’t know x 4, go to x 2 and then double it
Ex: 4 x 8 = go to 2 x 8
= (2 x 8) double it
= 16 double it
4 x 8 = 32
MULTIPLY BY 8
Double the 4’s
If I don’t know x 8, go to x 4 and then double it (x 2)
8 x 6 = go to 4 x 6 double it
= 24 double it
8 x 6 = 48
MULTIPLY BY 3
MEMORIZE THEM!!!
MULTIPLY BY 6
Double the 3’s
If I don’t know x 6, go to x 3 and then double it (x 2)
8 x 6 = go to 4 x 6 double it
= 24 double it
8 x 6 = 48
Examples:
3 x 6 = (3 x3) x 2
= 9 x 2
= 18
MULTIPLY BY 7
MEMORIZE THEM!!!
TEST YOURSELF AT THE FOLLOWING SITES:
http://www.math-drills.com/multiplication/mult_v100_1212_0112_001.html
http://www.ixl.com/math/grade-3/multiplication-facts-to-12
TEST YOURSELF AT THE FOLLOWING SITES:
http://www.ixl.com/math/grade-3/multiplication-facts-to-12
http://www.math-drills.com/multiplication/multiplication_facts_to_81_target09_001.pdf
This presentation was created with the help of the After School Group:
Jayllia Brewer – 6th Gr
Gianna Sharp – 6th Gr
Kennedy Riley – 4th Gr
Hallie Williams – 6th Gr
Avery Ross – 6th Gr
Davion Rhone – 6th Gr
Tikayla Wade – 6th Gr