Objective: Today will learn how to multiply numbers with 2
digits by numbers with 1 digit. Example: 34 x 9
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Why do we need to know the Multiplication Properties? It helps
you solve problems without working them out. It helps with mental
math. It makes understanding math easier.
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Vocabulary To Know: Factor Product Commutative Property
Associative Property Identity Property Zero Property Distributive
Property
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Factor The numbers that are multiplied together in a
multiplication problem. Example: 34 x 9 = 306
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Product The answer to a multiplication problem. Example: 34 x 9
= 306
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Commutative Property of Multiplication The order that factors
(numbers) are multiplied will not change the product (answer).
Example: 56 x 4 = 4 x 56
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Commutative Property of Multiplication Lets Practice: 1. 34 x 8
= ____ x 34 2. 5 x ____ = 62 x 5 3. ____ x 9 = 9 x 71
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Associative Property of Multiplication The way that factors
(numbers) are grouped will not change the product (answer).
Example: (21 x 3) x 9 = 21 x (3 x 9)
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Associative Property of Multiplication Lets Practice: 1. 34 x
(___ x 6) = (34 x 8) x 6 2. (431 x 6) x 3 = ___ x (6 x 3) 3. 19 x
(___ x ___) = (19 x 2) x 7
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Zero Property of Multiplication Any factor (number) multiplied
by 0 will equal 0. Example: 679 x 0 = 0
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Zero Property of Multiplication Lets Practice: 1. 43 x 0 = ____
2. 35 x ____ = 0
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Identity Property of Multiplication Any factor (number)
multiplied by 1 will equal that number. Example: 679 x 1 = 679
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Identity Property of Multiplication Lets Practice: 1. 55 x 1 =
____ 2. 77 x ____ = 77
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Distributive Property of Multiplication When two addends are
multiplied by a factor the product will be the same as when each
addend is multiplied by the factor and the products are added.
Example: (2 + 3) x 4 = (2 x 4) + (3 x 4)
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Distributive Property of Multiplication Lets Practice: 1. (2 +
6) x 34 = (___ x 34) + (___ x 34) 2. (6 + 9) x 16 = (___ x 16) +
(___ x 16) 3. (4 + 5) x 23 = (4 x ___) + (5 x ___) 4. (___ + 3) x
11 = (7 x 11) + (3 x 11) 5. (___ + ___) x 90 = (4 x 90) + (1 x
90)
Slide 18
Multiplication Steps 1. Write the problem lining up the place
values (ones under ones). 2. Multiply the bottom number in the ones
place by the top number in the ones place. 3. Write the answer
below the problem in the ones place. Regroup if necessary. 4.
Multiply the bottom number in the ones place by the top number in
the tens place and add the number you carried if you have one. 5.
Write the answer below the problem in the tens place. 2 Digit x 1
Digit
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Start Here 2 1
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2 Digit x 1 Digit 5 2 1 21 0 1 6
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Hand Trick: UP then OVER!
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2 Digit x 1 Digit 4 2 1 36 2 1 2 5
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Hand Trick: UP then OVER!
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2 Digit x 1 Digit 7 2 1 99 3 6 6 9
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Hand Trick: UP then OVER!
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You Try One 6 2 1 48 4 2 5 0
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You Try Another 8 91 2 7 1 5
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9 13 92 7 You Try Another
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3 Digit x 1 Digit 5 21 0 1 6 2 1 0 1 1 2, 3 3
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3 Digit x 1 Digit 3 93 7 2 1 6 1 9 1 1 2, 3 3 1
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Independent Practice 1. 14 x 5 = 2. 62 x 2 = 3. 234 x 9 = 4. 45
x 7 = 5. 87 x 4 = 6. 28 x 1 = 7. 26 x 3 = 8. 343 x 6 = 9. 54 x 8 =
10. 414 x 3 = 2 & 3 Digit x 1 Digit
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2 Digit x 2 Digit Steps Start Here 21 0 21 Step 1: Write the
problem making sure you line up the correct place values. Step 2:
Do the green steps first. Step 3: Mark out the number you carried
and add a zero to hold the ones place. Step 4: Do the red steps
next. Step 5: Add the green and red answers together.
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Hand Trick: UP then OVER and OVER then UP!
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1 2 Digit x 2 Digit 21 0 21 Step 1: Write the problem making
sure you line up the correct place values. Step 2: Do the green
steps first. Step 3: Mark out the number you carried and add a zero
to hold the ones place. Step 4: Do the red steps next. Step 5: Add
the green and red answers together. 46 23 81 3 2 1 9 8 5 1 0,
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Hand Trick: UP then OVER and OVER then UP!
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2 Digit x 2 Digit 21 0 21 Step 1: Write the problem making sure
you line up the correct place values. Step 2: Do the green steps
first. Step 3: Mark out the number you carried and add a zero to
hold the ones place. Step 4: Do the red steps next. Step 5: Add the
green and red answers together. 83 52 61 6 5 1 4 1 6 1 3, 1 4
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Hand Trick: UP then OVER and OVER then UP!
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3 2 Digit x 2 Digit 0 Step 1: Write the problem making sure you
line up the correct place values. Step 2: Do the green steps first.
Step 3: Mark out the number you carried and add a zero to hold the
ones place. Step 4: Do the red steps next. Step 5: Add the green
and red answers together. 94 38 27 5 2 1 2 8 2 7 5,3 1
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Hand Trick: UP then OVER and OVER then UP!
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2 2 Digit x 2 Digit 0 Step 1: Write the problem making sure you
line up the correct place values. Step 2: Do the green steps first.
Step 3: Mark out the number you carried and add a zero to hold the
ones place. Step 4: Do the red steps next. Step 5: Add the green
and red answers together. 85 25 54 2 0 1 1 7 5 2 1,2 1
Slide 41
1 You try one 0 Step 1: Write the problem making sure you line
up the correct place values. Step 2: Do the green steps first. Step
3: Mark out the number you carried and add a zero to hold the ones
place. Step 4: Do the red steps next. Step 5: Add the green and red
answers together. 23 14 2 9 32 2 2 3 1
Slide 42
2 You try another 0 Step 1: Write the problem making sure you
line up the correct place values. Step 2: Do the green steps first.
Step 3: Mark out the number you carried and add a zero to hold the
ones place. Step 4: Do the red steps next. Step 5: Add the green
and red answers together. 73 48 45 8 2 1 2 9 4 0 5,3 1 1
Slide 43
Independent Practice 1. 26 x 35 = 2. 62 x 41 = 3. 34 x 99 = 4.
45 x 74 = 5. 87 x 73 = 6. 28 x 12 = 7. 26 x 37 = 8. 43 x 62 = 9. 54
x 86 = 10. 44 x 38 = 2 Digit x 2 Digit
Slide 44
What do you think the steps will be to multiply a 3 Digit x a 2
Digit? 548 x 19 423 x 25 937 x 62 3 Digit x 2 Digit
