Unit 2 Math Review

What multiplication number sentence is shown in the array

modeled below?

Answer: 12 x 3 = 36

What is another way to solve

63 + 63 + 63 + 63 + 63?

Answer: 63 x 5

Write a multiplication expression you could use to solve the following:125 + 125 + 125 + 125?

Answer: 125 x 4

What is 1,789 rounded to the nearest

hundred?

To the nearest thousand?

Answer: 2,000

What is 8,498 rounded to the nearest

hundred?

To the nearest thousand? Answer: 8,000

Use partial products to calculate 35 X 4.

Answer: 35 x 4 20 + 120 140

Use partial products to calculate 125 X 9.

Answer: 125 x 9 45 180 + 900 1,125

Use the distributive property (breaking

apart) to find 5 X 14.

Answer: (5 x 10) + (5 x 4) 50 + 20 70

Use the distributive property to find 8 X 18.

Answer: (8 x 10) + (8 x 8) 80 + 64 144

Use the distributive property to find the

product of 8 X 115.

Answer: (5 x 100) + (8 x 10) + (8 x 5) 500 + 80 + 40 620

Tim is multiplying 36 by 7. What are the two partial products he would add to find the product?

30 + 6 X 7

Which addition sentence shows how to use partial products to find 5 × 17?

A.    50 + 35 = 85

B.    17 + 5 = 175

C.    5 + 35 = 40

Write the number sentence you would use to solve the problem below.

48 x 3 = 144

Multiply 93 × 7.

651

Multiply 58 × 6.

348

Multiply 258 × 4.

1,032

Multiply 5,238 × 4.

20,952

Darnell needs to buy new pastels. He picks sets with 36 different colors. How many new pastels will she have if he buys 5 new sets?

36 x 5 = 180

In a class, 12 students will present their history projects. Each student gets to talk for 7 minutes. How much time is needed to present all of the history projects?

84 minutes

Picasso’s sells 365 pizzas in one week. How many pizzas do they sell in 5 weeks?

Answer: 1,725

Zachary read for 28 minutes a day, 4 days a week. What is the total

number of minutes Zachary read in 5

weeks?

Answer: 500 minutes

Each table in the cafeteria at Hillview School seats 16 children. How many children can be seated at 4 tables if there are no empty seats?

64 children

There are 12 months in one year. If McKenna has been alive for 8

years, what would be a reasonable estimate for the number of months

she has been alive?

Answer: approximately 80 months

Genna plans on driving 285 miles each day on his trip across the country. Write a number sentence that can be used to estimate the total number of miles she will drive in the first 5 days?

300 x 5 = 1,500

A race track is 7 miles long. Daniel drove around the track 27 times. He used estimation to find out how far he drove.

First, he multiplied 30 X 7 = 210. Write the next 2 steps to find the actual distance he drove.

Answer: 1. Multiply 3 x 7 = 21 2. Subtract 21 from 210

There are 9 classrooms in the C2 Commons. Each class brought in 39 items for the food drive. The Kids Helping Kids Club used estimation to figure out how many items the C2 Commons brought in. First they multiplied 40 X 9 = 360. What should they do next to determine the actual number of items that were brought in?

Answer: Multiply 1 x 9 = 9 (then subtract from 360)

Which is the same as 4 × 46?

A.    160 + 24

B.    160 + 16

C.    240 + 16

Which is the same as 3 × 52?

A.    150 + 5

B.    150 + 15

C.    150 + 6

Christopher is at the book fair and wants to buy a book and a bookmark for each of the 6 members of his family. He has $40 with him. If the books are $4 each and the bookmarks are $2 each will he have enough money to buy everything?

Answer: yes

William Street School has 4 parking lots with an average of 32 cars in each lot. Is 120 a

reasonable estimate for the number of cars at William Street School?

Julie and her family drive to Florida 3 times each year to go to Disney World. The distance there and back is 2,390 miles. What is the total distance that they drive each year on their trips to Florida?

Answer: 7,170

Rosie and Joey made Christmas cards. Rosie made 12 Christmas cards and Joey made 3 times as many cards as Rosie. How many cards did they make total?

Answer: 48

There are 15 boys in fourth grade chorus.

There are twice as many girls as boys in chorus. How many

children are in fourth grade chorus?

Answer: 45

Danny has 5 times as many baseball cards as Ken. Ken has 15 fewer baseball cards than Andrew. Andrew has 30 baseball cards. How many cards does Danny have?

Answer: 75

There are 15 boys in fourth grade chorus.

There are twice as many girls as boys in chorus. How many girls are in fourth

grade chorus?

Answer: 30

Sally has 6 times as many songs on her I-Pod than Katie. Katie has 8 fewer songs than Sarah. Sarah has 32 songs. How many songs does Sally have?

Answer: 156

Dominic earns $9 per hour at his job. Last week he worked 27 hours. Write a number sentence that can be used to estimate the total amount of money Dominic earned last week.

30 x $9 = $270

One car on the commuter train holds 172 passengers. Write a number sentence that can be used to estimate the total number of passengers that 6 train cars can hold?

200 x 6 = 1,200 passengers

Use mental math to find the product. 9 × 62

60 x 9 = 540

2 x 9 = 18

540 = 18 = 558

The school ordered 4 cases of water for the cafeteria vending machine. Each case has 32 bottles of water. What is a reasonable estimate of the number of bottles of water the school ordered?

30 x 4 = 120 water bottles

A flower shop sells many kinds of bouquets. Below is part of a bouquet chart. How many stems are needed for 7 bouquets of daisies?                                                                                                                                                                                     

24 x 7 = 168 stems