Multiplication: An Adventure in Number Sense
Summary of Patterns: No Need to Memorize...
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Put together, in your own words or pictures or objects, all the patterns that you have discovered and learned in connection with multiplication table. How many patterns do you have so far? Ask other people to share their patterns. |
Here are some examples of patterns:
|
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
1 |
1*1=1 |
1*2=2 |
1*3=3 |
1*4=4 |
1*5=5 |
1*6=6 |
1*7=7 |
1*8=8 |
1*9=9 |
1*10=10 |
2 |
2*1=2 |
2*2=4 |
2*3=6 |
2*4=8 |
2*5=10 |
2*6=12 |
2*7=14 |
2*8=16 |
2*9=18 |
2*10=20 |
3 |
3*1=3 |
3*2=6 |
3*3=9 |
3*4=12 |
3*5=15 |
3*6=18 |
3*7=21 |
3*8=24 |
3*9=27 |
3*10=30 |
4 |
4*1=4 |
4*2=8 |
4*3=12 |
4*4=16 |
4*5=20 |
4*6=24 |
4*7=28 |
4*8=32 |
4*9=36 |
4*10=40 |
5 |
5*1=5 |
5*2=10 |
5*3=15 |
5*4=20 |
5*5=25 |
5*6=30 |
5*7=35 |
5*8=40 |
5*9=45 |
5*10=50 |
6 |
6*1=6 |
6*2=12 |
6*3=18 |
6*4=24 |
6*5=30 |
6*6=36 |
6*7=42 |
6*8=48 |
6*9=54 |
6*10=60 |
7 |
7*1=7 |
7*2=14 |
7*3=21 |
7*4=28 |
7*5=35 |
7*6=42 |
7*7=49 |
7*8=56 |
7*9=63 |
7*10=70 |
8 |
8*1=8 |
8*2=16 |
8*3=24 |
8*4=32 |
8*5=40 |
8*6=48 |
8*7=56 |
8*8=64 |
8*9=72 |
8*10=80 |
9 |
9*1=9 |
9*2=18 |
9*3=27 |
9*4=36 |
9*5=45 |
9*6=54 |
9*7=63 |
9*8=72 |
9*9=81 |
9*10=90 |
10 |
10*1=10 |
10*2=20 |
10*3=30 |
10*4=40 |
10*5=50 |
10*6=60 |
10*7=70 |
10*8=80 |
10*9=90 |
10*10=100 |
| Twin
facts: because of the commutative law, once you know one of the pair
of twin facts, you know both of them. In other words, a*b = b*a
for any numbers a and b.
Example: 7*9 = 9*7 = 63 |
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| Times 10:
to multiply a whole number by 10, write an extra zero at the end of
the number.
Example: 5*10 = 50 |
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| Times 1:
to multiply a number by 1, do nothing.
Example: 8*1 = 8 |
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| Times 9:
To multiply a number by 9, multiply it by 10 and subtract the number. Or
use your hands.
Example: 9*7 = 10*7 - 7 = 70 - 7 = 63 To do it on hands, bend finger #7 from the left.
There are six fingers to the left of the bent finger, and three fingers to the right. So we have 9*7=63 |
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| Times 5:
To multiply a number by 5, multiply a half of that number by
10.
Example: 5 times 8 is the same as four 10s, or 40, so 5*8 = 40 |
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| Times 2: to multiply a number by two, add it to itself. | ||||||||||
| Off
diagonal: To multiply numbers that differ by two, multiply the
number between them by itself and subtract one.
Example: 6*8 = 7*7 - 1 = 48 |
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| © Copyright 1998 by Maria Droujkova and Dmitri Droujkov. All rights reserved. No part of these materials should ever be used in any situation that involves compulsory teaching. See also copyright notes and student rights. |
