Helpful Tricks and Hints for Math
Multiplication Facts…Tricks and Tips
As a class, we have come up with some catchy tunes, mostly Christmas carols, to help us remember our multiplication facts.
2’s - Chant
3’s – Jingle Bells
4’s – Dashing Through The Snow
5’s – Chant
6’s – Frosty the Snowman
7’s - Happy Birthday or Joy to the World
8’s – Rudolph the Red-Nosed Reindeer
9’s - We Wish you a Merry Christmas
10’s – Chant
11’s - Santa Claus is Coming to Town
12’s – Deck the Halls
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11 Times Rule #1
1. Take any number to 10 and multiply it by 11.
2. Multiply 11 by 3 to get 33, multiply 11 by 4 to get 44. Each number to 10 is just duplicated.
11 Times Rule #2
1. Use this strategy for two digit numbers only.
2. Multiply 11 by 18. Jot down 1 and 8 with a space between it. 1 --8.
3. Add the 8 and the 1 and put that number in the middle: 198
12 Times Rule
- Multiply the number by 10
- Multiply the number by 2
- Add both products together.
Tricks by Number
to multiply
by
Trick
2
add the number to itself (example 2×9 = 9+9)
5
the last digit goes 5, 0, 5, 0, ...
is always half of 10× (Example: 5x6 = half of 10x6 = half of 60 = 30)
is half the number times 10 (Example: 5x6 = 10x3 = 30)
6
when you multiply 6 by an even number, they both end in the same digit.
Example: 6×2=12, 6×4=24, 6×6=36, etc
9
the last digit goes 9, 8, 7, 6, ...
your hands can help! Example: to multiply 9 by 8, hold your 8th finger down, and count "7" and "2", the answer is 72
is 10× the number minus the number. Example: 9×6 = 10×6−6 = 60−6 = 54
when you add the answer's digits together, you get 9.
Example: 9×5=45 and 4+5=9. (But not with 9×11=99)
10
put a zero after it
11
up to 9x11: just repeat the digit (Example: 4x11 = 44)
for 10x11 to 18x11: write the sum of the digits between the digits
Example: 15x11 = 1(1+5)5 = 165
Note: this works for any two-digit number, but when the sum of the digits is more than 9, we need to"carry the one". Example: 75x11 = 7(7+5)5 = 7(12)5 = 825.
12
is 10× plus 2×
3…6…9……12…15…
Jingle bells, jingle bells,
18…21
Jingle all the way.
24…27,
Oh! what fun it is to ride
30…33
In a one-horse open sleigh.
And 36!
4…8…12…16
Dashing through the snow
20…24
In a one-horse open sleigh
28..32…36..40
O'er the fields we go
Laughing all the way
Ohh…44…48..lalalalalaaa
Jingle Bells, Jingle Bells
6…12….18…
Frosty the snowman
24….30…36
was a jolly happy soul,
42…48…54…60
With a corncob pipe and a button nose
66….72
And two eyes made out of coal.
7..14..21
Happy Birthday to you!!!
28…35
Happy Birthday to you!!!
42..49..56..63
Happy Birthday dear meeeee!!!
70, 77, 84
8, 16, 24
Rudolph the red-nosed reindeer
32, 40
Had a very shiny nose
48, 56
And if you ever saw him
64, 72
You would even say it glows….
80, 88, 96
Then on Foggy Christmas Eve
Santa Came to say……=)