Arrays of Multiplying two- digit by multiples of 10
Multiplying multiples of 10
Rounding to Estimate
Compatible numbers and more estimating
Multi-step word problems
100
The dentist ordered 10 boxes of toothbrushes. There are 15 toothbrushes in each box.
How many toothbrushes did the dentist order? Use the array to help.
C) 150
100
Use mental math to find the product. 10 × 50
500
100
Carl volunteers about 32 hours each month at the local hospital.
What is the best estimate of how many hours he volunteers in 12 months?
A) 600 hours
B) 300 hours
C) 40 hours
D) 32 hours
B) 300 hours
100
A park ranger takes 24 groups of people hiking each week.
There are 32 people in each group.
What is the best estimate of how many people hike with the park ranger each week?
A) 1,000
B) 750
C) 500
D) 400
B) 750
100
Fourteen students in Ms. Engel's class have 2 pets. Three students have 1 pet.
There are 3 students that do not have any pets. How many pets does the class have all together?
A) 3
B) 20
C) 23
D) 31
D) 31
200
This array shows 26 rows of 30 squares.
Which sentence shows how to find the number of shaded squares?
A) 6 × 10 = 60
B) 20 × 30 = 600
C) 6 × 30 = 180
D) 10 × 30 = 300
C) 6 x 30= 180
200
Every day, 60 people eat at Franco's Diner. How many people eat there in 30 days?
A) 2,000
B) 1,800
C) 180
D) 90
B) 1,800
200
Estimate by rounding to the nearest ten. 73 × 37
A) 2,100
B) 2,800
C) 210
D) 280
B ) 2,800
200
A toy store ordered 26 crates of stuffed bears.
There are 21 stuffed bears in each crate.
What is the best estimate of how many stuffed bears the store ordered?
A) 1,000
B) 900
C) 500
D) 400
C) 500
200
Aspen is setting up chairs for a concert. One section will have 5 equal rows of 5 chairs each.
The other section will have 8 equal rows of 2 chairs each. How many chairs will there be in all?
A) 41
B) 36
C) 35
D) 20
A) 41
300
This array shows 26 rows of 30 squares.
Which sentence shows how to find the number of shaded squares?
A) 6 × 10 = 60
B) 20 × 30 = 600
C) 6 × 30 = 180
D) 10 × 30 = 300
B ) 20 X 30 = 600
300
Each of the 90 fourth-grade students at North Elementary read 30 books over the school year.
How many books did they read all together?
2,700 books
300
Coach Cody ordered 22 shirts for team members. Which is the best estimate of the total cost of the shirts, before tax?
A) less than $400
B) between $400 and $750
C) between $750 and $900
D) more than $900
B ) between $400 and $750
300
Which estimate is closest to 81 × 28?
A) 80 × 20 = 1,600
B) 80 × 30 = 2,400
C) 90 × 20 = 1,800
D) 90 × 30 = 2,700
B) 80 x 30= 2,400
300
The gym teacher has 4 yoga tapes. She has 3 times as many dance tapes as yoga tapes.
How many yoga and dance tapes does she have in all?
A) 43
B) 34
C) 16
D) 12
C) 16
400
This array shows 24 rows of 30 squares. Which is a way to find the total number of squares?
A) 600 + 120
400
At the end of the year Molly has been assigned to clean 30 desks in a classroom. Each desk takes 10 minutes to clean. How much time is needed for Molly to clean all the desks?
A)30 minutes
B) 2,000 minutes
C) 300 minutes
D) 200 minutes
300 minutes
400
Cindy earns $36 a week at her part-time job. Which is the best estimate of how much Cindy earns in a year? Remember there are 52 weeks in a year.
A) $1,500
B) $1,000
C) $2,000
D) $2,400
$2,000
400
Estimate. Which plants cost more than $600 in all?
A) 38 plants for $11 each
B) 27 plants for $18 each
C) 21 plants for $19 each
D) 32 plants for $20 each
D) 32 plants for $20 each
400
Marsha buys 6 necklaces for $8 each. She buys 3 pairs of earrings for $14 each. How much money does Marsha spend in all?
$90
500
This array shows 24 rows of 30 squares.
Which sentence shows how to find the number of shaded squares?
A) 20 × 30 = 600
B) 4 × 30 = 120
C) 10 × 30 = 300
D) 4 × 10 = 40
A) 20 x 30 = 600
500
Use mental math. Which product is 2,400?
A) 20 × 40
B) 30 × 90
C) 30 × 80
D) 40 × 70
C) 30 x 80
500
*** EXTRA 100 POINTS
Mary has 13 spools of rope. Each spool holds between 36 and 45 meters of rope. Which could be the total number of meters of rope she has on these spools?
(Hint: estimate 13 x 36 and then estimate 13 X 45 and see what answer its near below)
A) 500 m
B) 400 m
C) 650 m
D) 350 m
A) 500 m
500
Estimate. Which concert tickets cost less than $600 in all?
A) 42 tickets for $18 each
B) 39 tickets for $28 each
C) 34 tickets for $24 each
D) 26 tickets for $21 each
D) 26 tickets for $21 each
500
Catrina bought 3 rings at $4 a ring and 4 bracelets at $6 a bracelet. She paid with two $20-bills. How much change did she receive?
$4