Solved Examples and Worksheet for Multiplying One-Digit Numbers with Multiples of 10

Q1There are 60 minutes in an hour. Find the number of minutes in 5 hours.
A. 60
B. 300
C. 65
D. 350

Step: 1
Number of minutes in 5 hours = 60 × 5
[There are 60 minutes in one hour.]
Step: 2
= 6 × 10 × 5
[60 = 6 × 10.]
Step: 3
= 6 × 5 × 10
[Use commutative property.]
Step: 4
= 30 × 10 = 300
Step: 5
So, there are 300 minutes in 5 hours.
Q2Mrs. Jessica's family moved from New Zealand to Australia. They carried 7 suitcases each weighing 80 lb. How much did their luggage weigh altogether?
A. 87 lb
B. 570 lb
C. 560 lb
D. 807 lb

Step: 1
The weight of the total luggage of Mrs. Jessica's family = the number of suitcases × the weight of each suitcase
Step: 2
= 7 × 80
[Substitute the values.]
Step: 3
= 7 × 8 × 10
[8 × 10 = 80]
Step: 4
= 56 × 10 = 560

Step: 5
The luggage weighed 560 lb altogether.
Correct Answer is :   560 lb
Q3A file holder has 5 shelves. Each shelf has 20 files. How many files does the file holder have in all?
A. 110
B. 100
C. 25
D. 4

Step: 1
Total number of files with the holder = the number of shelves × the number of files in each shelf
Step: 2
= 5 × 20
Step: 3
= 5 × 2 × 10 = 100
[From the multiplication table of 5.]
Step: 4
So, the file holder has 100 files in all.
Q4The product of 20 and 3 is equal to ________ .
A. 65
B. 30
C. 60
D. 63

Step: 1
The product of 20 and 3 is 20 × 3.
Step: 2
20 × 3 = 60
[From the multiplication table of 20.]
Q5There are 40 cards in a box. Find the number of cards in 5 boxes.

A. 200
B. 40
C. 250
D. 150

Step: 1
Number of cards in a box = 40 = 4 × 10
Step: 2
Number of card in 5 boxes = 5 × 40
Step: 3
= 5 × 4 × 10 = 20 × 10
Step: 4
= 200
Step: 5
So, there are 200 cards in 5 boxes.
Q6Find the value of 5 × 50.
A. 25
B. 250
C. 2,500
D. 25,000

Step: 1
5 × 5 = 25
[Multiply.]
Step: 2
5 × 50 = 250
[Since there is one zero at the end of 5 put one zero at the end of 25.]
Q7Mr.David along with his family members went to a tour. He carried 4 suitcases each weighing 70 lb. How much did their luggage weigh altogether?
A. 280 lb
B. 270 lb
C. 300 lb
D. 470 lb

Step: 1
The weight of the total luggage of Mr.David's family = the number of suitcases × the weight of each suitcase.
Step: 2
= 4 × 70
[Substitute the values.]
Step: 3
= 280.
[Multiply.]
Step: 4
The luggage weighed 280 lb altogether.
Correct Answer is :   280 lb
Q8The product of 90 and 4 is equal to ________ .

A. 364
B. 40
C. 356
D. 360

Step: 1
The product of 90 and 4 is 90 × 4.
Step: 2
90 × 4 = 360
[From the multiplication table of 90.]
Q9The product of 40 and 5 is equal to ________ .

A. 200
B. 195
C. 205
D. 50

Step: 1
The product of 40 and 5 is 40 × 5.
Step: 2
40 × 5 = 200
[From the multiplication table of 40.]