Topic 3: Fluently Multiply Multi-Digit Whole Numbers

Multiplying by Powers of 10

100

34 x 10

340

200

296 x 100

29,600

300

How many zeros would be in the product of:

20 x 1,000

4 zeros

400

30 x 10²

3,000

500

120 x 10³

120,000

Estimating Products

100

32 x 70

30 x 70 = 2,100

200

23 x 62

25 x 60 = 1,500 

or

20 x 60 = 1,200

300

117 x 48

100 x 50 = 5,000 

or

120 x 50 = 6,000

400

305 x 79

300 x 80 = 24,000

500

A theater has 197 seats.  A ticket to the theater costs $24.

If all the seats are filled for 1 show, estimate how much the theater will make in ticket sales.  

200 x 25 = $5,000

or 

200 x 20 = $4,000

Multiplying Double Digit by Double Digit

100

34 x 78

2,652

200

30 x 56

1,680

300

99 x 74

7,326

400

25 x 85

2,125

500

54 x 63

3,402

Multiplying Triple Digit by Double Digit

100

876 x 54

47,304

200

853 x 64

54,592

300

412 x 98

40,376

400

402 x 68

27,336

500

999 x 99

98,901

Word Problems

100

Jamie has 334 songs on Spotify.  Sam has 18 times as many songs on Spotify.  How many songs does Sam have?

6,012 songs

200

A movie theater that has 325 seats is playing a movie 15 times in a weekend.  The theater is sold out for each movie.  How many people will be seeing this movie that weekend?

4,875 people

300

Sharon buys staples for her stapler that come in boxes of 545 staples per box.  She buys 22 boxes for her office at work.  How many staples does she have in all?

11,990 staples

400

A warehouse has a certain chair that weighs 228 pounds.  The warehouse has 44 of these chairs.  What is the total weight of all the chairs?

10,032 pounds

500

Leah ordered 1,296 Pokemon cards.  Steven ordered 3 times as many as Leah.  Write and solve an equation to find p, the number of Pokemon cards Steven ordered.

1,296 x 3 = p

p = 3,888 cards