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Name:_________________
C.L.M.S. Grade 6 Math:
Multiplication Tips
Ever wonder how some people seem to know their multiplication facts so easily? Many
people use tricks to help them figure out multiplication problems quickly and easily.
Rather than having to memorize all of the multiplication facts (which number in the
hundreds) by heart, with the following tricks you should only really have to remember
about five of them:
The six facts that you will have to memorize are:
6 x 6 = 36,
6 x 7 = 42,
6 x 8 = 48,
7 x 7 = 49, 7 x 8 = 56,
8 x 8 = 64
We can make up a song to help us remember those later, but in the mean time, let’s learn
the tricks which should help us figure out all of the other math facts. Remember that
these are tricks which can help you multiply if you have trouble with math facts or help
you check your answer if you already have them down pat.
Multiplying by zero:
We all know this trick already. Any number times 0 is 0. Simple.
Just for kicks, see how fast you can solve the following problems (wait for Mr. Claude to
say go):
A) 5 x 0 =____ B) 0 x 9= ______ C) 1228949898 x 0 = _____ D) -4588276 x 0=_____
Multiplying by one:
Just as easy. Any number times one is (of course) the number itself.
Remember to wait for Mr. Claude to say go:
A) 7 x 1 _____ B)1 x 253 = ______C) 2896 x 1=______ D) -345 000 x 1= __________
Multiplying by two “Doubling”:
From the age of 3 or 4 we start to be able to double things in our heads. That’s all that
multiplying by two is. It gets a little bit trickier of course with bigger numbers, but most
of us have no trouble doubling numbers that are smaller than ten.
Give it a try!
Remember to wait for Mr. Claude to say go:
A) 9 x 2 = _____ B) 2 x 7 = ______ C) 2 x 4000 = ______ D) 8000 x 2 = __________
Multiplying by threes “Doubling and adding the number”:
Since doubling comes to us so naturally, multiplying by three should be pretty easy too.
Multiplying by three is just doubling a number and then adding the original number.
Example: 3 x 7 = double7 + 7
(14)
(21)
3 x 19 = double19 + 19
(38)
(57)
Your turn!
Remember to wait for Mr. Claude to say go:
A) 3 x 6=_____ B) 3 x 7 = _____ C) 3 x 8 = ______ D) 3 x 12 = ______
Multiplying by fours “Double doubling”:
Multiplying by four is really just doubling a number and then doubling it again. Since
doubling is so easy, this should be a walk in the park.
e.g. 4 x 7 = double 7
(14)
double 14
(28)
Give it a try:
A) 4 x 8 =_____ B) 4 x 9 =______ C) 4 x 12 = ______ D) 4 x 24 = ______
Multiplying by fives “Attaching a zero and then halving” or Noticing 5s:
There are more than one trick for multiplying by 5. The first is halving the number and
then moving up a step in place value.
e.g. 5 x 6 = half of 6, and move up a step
(3)
(30)
7 x 5 = half of 7, and move up a step
(3.5)
(35)
You can also attach a zero (multiply by ten) and then halve the number (divide it by two):
e.g. 5 x 6 = attach a zero, then halve the number 7 x 5= attach a zero, then halve the number
(60)
( 30)
(70)
(35)
Noticing 5s
The third trick when multiplying fives is to notice the pattern that multiples of 5 share.
All even numbers multiplied by 5 produce a number ending in zero. All odd numbers is
noticing the pattern when you multiply by 5s. All odd numbers ending in 5 produce a
number ending in 5.
Use any of the above methods and give these problems a try:
A) 5 x 4 = _____B) 7 x 5 =____ C) 5 x 8= ____ D) 5 x 13 = ____ E) 18 x 5= _____
Multiplying by 9 “Noticing nines”, “Almost perfect”:
Multiples of 9 that are below 100 follow a clear pattern. When you list the multiples of
nine you’ll notice that as the first digit gets bigger, the second digit gets smaller:
09
18
27
36
45
54
63
72
81
90
You may also notice that if you add the digits together in a multiple of nine, they will
always equal 9.
e.g.
18: 1 + 8 = 9,
27: 2 + 7 = 9,
36: 3 + 6 = 9,
45: 4 + 5 = 9 etc.
Knowing both of these patterns should help you check your work when you are
multiplying by nine. The clincher is the “almost perfect rule”.
“Multiples of 9 are almost perfect”
I like to think of multiples of 10 as perfect numbers (maybe because they’re easy to count
by, they end in zero etc.). If that’s true, then multiples of 9 are almost perfect. When
multiplying by nine, just think of what the multiple of 10 would be (by attaching a zero to
it) and then subtracting whatever number you’re multiplying by nine.
For example:
9 x 7 = 7 less than 70
9 x 6 = 6 less than 60
63
Now you try it:
54
9 x 45 = 45 less than 450
405
A) 9 x 8 = _____ B) 9 x 4 = _____ C) 9 x 12 = _____ D) 9 x 25 = _______
Multiples of 10 “Attach a zero”:
Very simple: e.g. 2 x 10 = 20,
1234 x 10 = 12340
Name:__________________
Multiplication Tricks: Practice your Skills
Use the tricks we have learned to solve the following problems.
Try to solve the problems mentally.
8x3=
7x5=
4x9=
7x3=
12 x 4 =
2x9=
8x4=
3x9=
4x9
4x8
3x 1 =
2x3=
8x2=
3x8=
4 x 10=
4x7=
11 x 4 =
2x4=
11 x 3 =
3x7=
3x3=
4x5=
3x6=
2x5=
8x9=
3x2=
3x5=
11 x 2 =
7x4=
2x6=
3x4=
4x3=
7x2=
2 x 7=
12 x 9=
5x9=
7x1=
2x8=
5 x 10 =
4x1=
12 x 5 =
2x1=
5x8=
9 x 10 =
10x 7 =
5x6=
7x9=
9x9=
5x4=
12 x 4
11 x 5 =
5x7=
5x5=
9x7=
5x3=
9x6=
10 x 6 =
10 x 9 =
5x2=
10 x 10
10 x 5 =
9x5=
5x1=
10 x 1 =
10 x 4 =
9x4=
10 x 3 =
10 x 8 =
10 x 2 =
23 x 2 =
12 x 3 =
9x3=
24 x 4 =
35 x 9 =
4 x 4=
19 x 9 =
240 x 3
9x2=
70 x 9 =
15 x 10=
4x2=
49 x 9 =
99 x 5=
9x1=
2348 x10 =
150 x 2 =
18 x 4
7x0=
11 x 3 =
9x0=
9x8=
11 x 9 =
4 x 6=
12 x 10 =
8x5=