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Word Problems
Rounding
Missing Factors and Vocabulary
Arrays
Area Models
100

The principal of a school needs to order the supplies for 20 new classrooms. Each classroom needs 20 desks, 30 chairs, and 40 pencils. How many of each items does the principal needs to order?

400 desks, 600 chairs, and 800 pencils

100

17 x 23

20 x 20= 400

100
When you multiply two number the outcome number is

product

100

20 x 26

20 +6

20 x 20 =40-

20x6 = 120 

400+120 = 520 


100

25 x 15

Split into 20 + 5 and 10 + 5

375

200

There are 10 teams in a basketball league. Each team has 25 players. How many players are in the league?

250  players

200

66 x 60 

70 x 60= 4200

200

A ______ shows the number of objects in rows and in columns

Array
200

30 x 26

30x20= 600

30 x6= 180 

600+180= 780

200

18 x 25

Split into 10 +8 and 20 + 5


450

300

Dr. Luca bough 28 notebooks. Each notebook has 54 pages. What is a good way to estimate the total number of pages

a.20 x 50                     c.30 x 50 

b. 20 x 60                    d. 28 x 60 

C. 30 x 50 

300

23 x 30 

20 x 30 = 600

300

The product of two factors is 1,200. One of the factors is 20.  What is the other factor?

A.40                        C. 60 

B. 120                     D. 600

C. 30 x 50 

300

10x16 

10 x10 = 100

10 x 6= 60 

100 + 60 = 160 

300

24 x 23

Split into 20 +4 and 20 +3

552

400

A bakery has 12 bins of bagels. Each bin is filled with 47 bagels. How many bagels are there?  

444 bagels

400

Which two expressions are equal to 420?

42 x100

40 x 100 + 20

40 x 10 +20 x10 

40 x10 +2x10 

20 x 10 +4 x10 

42 x 10 

40 x 10 +2 x10 

400

A number used that would make sense when estimating

Compatible Number

400

10 x 22

10 x 20= 200

10 x 2= 20

200+20 =220

400

35 x 12

Split into 30 +5 and 10+2


420

500

Nika has a contract and needs to make 37 beaded necklaces. She puts 42 beads in each necklace. Which is the best way to use rounding to estimate the number of beads Nika needs? What is the exact number of beads? 

A. 37 x40; 1,480              C. 40x40; 1,554

B. 40 X 42; 1680              D. 45 x 45; 2,025


C. 40 x 40; 1,554
500
Round to the hundreds place:


1167

1200

500

The lawn service charges $85 to mow, weed, and fertilize a lawn. How much did the lawn service earn if 15 lawns were tended in June and 23 lawns were tended in July?

$3,230

500

40 x21

40 x20=800

40x1=40

800+40=840

500

Graham Swims 14 laps 12 times in May. He swims14 laps in June draw an area model to find the number of laps Graham swam during the two months.

10x 10          14 x 10 

5x 10             14x 2         168 + 240= 480 laps

10 x6

5 x6