4th Gr. Go Math Ch. 2 (2.1-2.6)

Multiplication Comparisons

100

Write an equation:

21 is 7 times as many as 3

21 = 7 x 3

200

Write an equation:

4 times as many as 5 is 20

4 x 5 = 20

300

Write a comparison statement:

8 x 5 = 40

8 times as many as 5 is 40

400

Carly has 9 pennies. Jack has 4 times as many pennies as Carly. How many pennies does Jack have?

36

500

Miguel has 3 times as many rabbits as Sara. Miguel has 6 rabbits. How many rabbits does Sara have?

2

Multiply tens, hundreds, thousands

100

8 x 20

160

200

3 x 400

1,200

300

8 x 500

4,000

400

6 x 8 hundreds

48 hundreds

or

4,800

500

A bank teller has 7 rolls of coins. Each roll has 50 coins. How many coins does the bank teller have?

350 coins

Estimate Products

100

Estimate the product by rounding:

3 x 165

600

200

Estimate the product by rounding:

9 x 54

450

300

Estimate the product by rounding:

6 x 7,381

42,000

400

Find two numbers the exact answer is in between:

8 x 684

4,800 and 5,600

500

Isaac drinks 8 glasses of water each day. He says he will drink 2,920 glasses of water in a year that has 365 days. Is his exact answer reasonable? EXPLAIN!

Yes, his answer is reasonable because it is between the estimates of 2,400 and 3,200.

Distributive Property and Expanded Form

100

Multiply using distributive property:

6 x 18

6 x 10 = 60

6 x 8 = 48

60 + 48 = 108

200

Multiply using the distributive property:

8 x 15

8 x 10 = 80

8 x 5 = 40

80 + 40 = 120

300

Multiply using expanded form:

2 x 38

(2 x 30) + (2 x 8)

60 + 16

=76

400

Multiply using expanded form:

5 x 347

(5 x 300) + (5 x 40) + (5 x 7)

1,500 + 200 + 35

1,735

500

Multiply using expanded form:

8 x 1,293

(8 x 1,000) + (8 x 200) + (8 x 90) + (8 x 3)

8,000 + 1,600 + 720 + 24

10,344

Comparison Word Problems

100

Fred's frog jumped 7 times as far as Al's frog. The two frogs jumped a total of 56 inches. How far did Fred's frog jump?

49 inches

200

At the zoo, there were 3 times as many monkeys as lions. Tom counted a total of 24 monkeys and lions. How many monkeys were there?

18 monkeys

300

Stacey made a necklace using 4 times as many blue beads as red beads. She used a total of 40 beads. How many blue beads did Stacey use?

32 blue beads

400

Last month Kim trained 3 times as many dogs as cats. If the total number of cats and dogs she trained last month is 28, how many cats did Kim train?

Kim trained 7 cats

500

At the dog show, there are 4 times as many boxers as spaniels. 

a) If there are a total of 30 dogs, how many dogs are spaniels?

b) How many more boxers are there than spaniels?

a) 6 spaniels

b) 18 more boxers than spaniels