lets see what you know! mrs. flynns topic 3 math review are you ready? here are the concepts were...
DESCRIPTION
Practice Multiplying Tens 1.3 X 2 tens = 2.6 X 5 tens = 3.8 X 6 tens = 4.7 X 20 = 5.7 X 80 = 6.6 X 90 = 7.4 X 50 = 6 tens 30 tens 48 tens (60) (300) (480)TRANSCRIPT
Let’s see what you know!Mrs. Flynn’s Topic 3 Math Review
Are you ready?
Here are the concepts we’re
covering in math.
Multiplying by Multiples of Ten 4 X 20 = ?
Look for the basic fact to help you.
4 X 2 tens = 8 tensSo… 4 X 20 = 80
Basic fact Basic fact Basic fact
Practice Multiplying Tens
1. 3 X 2 tens = 2. 6 X 5 tens =3. 8 X 6 tens =
4. 7 X 20 =5. 7 X 80 =6. 6 X 90 =7. 4 X 50 =
6 tens 30 tens 48 tens
140560540200
(60) (300) (480)
Nicole builds 3 birdhouses in an hour & works 40 hours weekly.
How many birdhouses does she make each week?
3 birdhouses X 40 hours =
There are 20 chickens on John’s farm. Each lays 2 eggs each day.
How many eggs can John collect each week?
2 eggs X 20 chickens X 7 days =
Multiplying Using Patterns
Look for the basic fact to help you. 3 X 3 hundreds = 9 hundreds So… 3 X 300 = 900
Basic fact Basic fact Basic fact
Multiplication Patterns Use the same idea to help you multiply
larger numbers.
6 X 4 = 24
6 X 40 = 240
6 X 400 = 2,400
6 X 4,000 = 24,000
Practice! Find each product.
1. 5 X 90 =
2. 70 X 700 =
3. 6 X 5,000 =
4. 600 X 70 =
5. 8,000 X 3 =
450
49,000
30,000
42,000
24,000
Estimate means…
to find a number close to the exact
number.
Rounding to Estimate Products
Cheyenne collects books. She has 8 boxes. Each box holds about 38 books. How many
books does she have?
(38 rounds to 40)
Rounding to Estimate Products
Christian collects books. He has 18 shelves. Each shelf holds about 115 books. About how
many books does he have?
(115 rounds to 100)
(18 rounds to 20)
Rounding to Estimate ProductsCorey collects football cards. He has 5 albums.
Each album holds 45 cards. About how many football cards does Corey have?
(45 rounds to 50)
Now it’s your turn!
1. 567 X 52. 674 X 223. 7,881 X 64. 3,580 X 35. 6 X 2516. 4 X 3,6797. 72 X 1,814
600 X 5 = 3,000 700 X 20 = 14,000 8,000 X 6 = 48,000
4,000 X 3 = 12,000 6 X 300 = 1,800
4 X 4,000 = 16,000 70 X 2,000 = 140,000
Distributive Property with Arrays
What is an array? An array is an arrangement of
objects into rows and columns.
5 rows of 10
5 rows of 1
Practice! Draw arrays to help.
1. 73 X 7
2. 35 X 6
3. 59 X 4
4. 46 X 9
5. 26 X 3
70 X 7 = 490
30 X 6 = 180
50 X 4 = 200
40 X 9 = 360
20 X 3 = 60
3 X 7 = 21
5 X 6 = 30
9 X 4 = 36
6 X 9 = 54
6 X 3 = 18
490 + 21 = 511
180 + 30 = 210
200 + 36 = 236
360 + 54 = 414
60 + 18 = 78
Multiplication with Regrouping
Step One: Multiply the ones & regroup.+3
Multiplication with Regrouping
Step Two: Multiply the tens & add the extra tens.
+3+3
Multiplication with Regrouping
Try some with me!+2
+ 2 = 23
Multiplication with Regrouping
Try some with me!+1
+ 1 = 36
Multiplication with Regrouping
Try some with three digits!+5
+ 5 = 17
+1
+ 1 = 49
Multiplication with Regrouping
Try some with three digits!+2
+ 2 = 18
+1
+ 1 = 25
Multiplication with Regrouping
Try some multiplication with money!+2
+ 2 = 37
+3
+ 3 = 10
Multiplication with Regrouping
Try some multiplication with money!+7
+ 7 = 79
+7
+ 7 = 39
+ 3 = 11
+3
What is the Associative Property?
When the grouping of factors is changed, the product remains the same.
What is the Commutative Property?
When the order of factors is changed, the product remains the same.
Multiplying 3 Factors
The parentheses tell which factors to multiply first.
I know you’re going to do this on
a piece of paper, right?
Multiplying 3 Factors
The parentheses tell which factors to multiply first.
And you can do this in
your head, right?
Multiplying 3 Factors
The parentheses tell which factors to multiply first.
It’s all switched up, but it’s the same idea…
Multiplying 3 Factors
If there are no parentheses, multiply the smaller numbers first.
NO PROBLEMO,
MAN!
Okay.No
parentheses?
Pencil, paper, and practice!
1. 6 X 6 X 3 =
2. 3 X 9 X 1 =
3. 8 X 5 X 6 =
4. 4 X 3 X 11 =
5. 7 X 0 X 21 =
18 X 6 =
3 X 9 =
30 X 8 =
11 X 12 =
0 X 21 =
108
27
240
132
0
Problem Solving Fun!To raise money for the food drive, Kaitlyn sold 5 boxes of cards. Connor sold 3 boxes of candy bars. If a box of cards costs $2.99 and a box of
candy bars costs $5.25, how much did they earn?+4+4 +1
2 Digit by 2 Digit
Multiplication
36 X 23
Multiply the ones.
36 X 23
3 X 6 = 18 Regroup the ten.3 X 3 = 9 and one more is 10.
36 X 23 108
1
36 X 23 108Cross out the 1 after you use it.
1
NOW THINK:“I am multiplying 36 X 20.”
36 X 23 108
1st THINK:
“I am multiplying by tens so I need a zero.”
36 X 23 108 0
36 X 23 108 20
112 X 6 = 12
Put down the 2 and regroup the 1.
36 X 23 108 720
11
2 X 3 = 6
and
6 + 1 = 7
36 X 23 108 720
11
Cross out the number you regrouped after you add it.
Since multiplication is a form ofaddition, we need to group our
answers together.
Add the two partial productsto get the final product.
36 X 23 108 + 720 828
8 + 0 = 8
0 + 2 = 2
1 + 7 = 8
Exponents
The number that is repeatedly multiplied is called the ___________.
The _________________ shows the number of times the base is used as a factor.
The base is multiplied 3X
Write in Exponential Notation
1. Four squared =
2. Two cubed =
3. 5 X 5 X 5 X 5 =
4. 4 X 4 X 4 X 4 X 4 =
5. 6 to the 5th power =
Write in Standard Form
1. Four squared = =
2. Two cubed = =
3. 5 X 5 X 5 X 5 = =
4. 4 X 4 X 4 X 4 X 4 = =
5. 6 to the 3rd power = =
4 x 4 = 16
1,024
625
8
216