Welcome, visitor! [ Login

 

Common multiplication and division situations.

  • Listed: January 5, 2020 10:10 pm
  • Expires: 998417 days, 20 hours

Description

Table 2. Common multiplication and division situations.7

 

  Unknown Product Group Size Unknown

(“How many in each group?” Division)

Number of Groups Unknown

(“How many groups?” Division)

  3 x 6 = ? 3 x ? = 18, and 18 ¸ 3 = ? ? x 6 = 18, and 18 ¸ 6 = ?
Equal Groups There are 3 bags with 6 plums

in each bag. How many plums

are there in all?

Measurement example. You

need 3 lengths of string, each

6 inches long. How much string

will you need altogether?

If 18 plums are shared equally

into 3 bags, then how many

plums will be in each bag?

Measurement example. You

have 18 inches of string, which

you will cut into 3 equal pieces.

How long will each piece of

string be?

If 18 plums are to be packed 6

to a bag, then how many bags

are needed?

Measurement example. You

have 18 inches of string, which

you will cut into pieces that are

6 inches long. How many pieces

of string will you have?

Arrays,4

Area5

There are 3 rows of apples

with 6 apples in each row. How

many apples are there?

Area example. What is the area

of a 3 cm by 6 cm rectangle?

If 18 apples are arranged into 3

equal rows, how many apples

will be in each row?

Area example. A rectangle has

area 18 square centimeters. If

one side is 3 cm long, how long

is a side next to it?

If 18 apples are arranged into

equal rows of 6 apples, how

many rows will there be?

Area example. A rectangle has

area 18 square centimeters. If

one side is 6 cm long, how long

is a side next to it?

Compare A blue hat costs $6. A red hat costs 3 times as much as the

blue hat. How much does the

red hat cost?

Measurement example. A

rubber band is 6 cm long. How

long will the rubber band be

when it is stretched to be 3

times as long?

A red hat costs $18 and that is

3 times as much as a blue hat

costs. How much does a blue

hat cost?

Measurement example. A

rubber band is stretched to be

18 cm long and that is 3 times

as long as it was at first. How

long was the rubber band at

first?

A red hat costs $18 and a blue

hat costs $6. How many times

as much does the red hat cost

as the blue hat?

Measurement example. A

rubber band was 6 cm long at

first. Now it is stretched to be

18 cm long. How many times as

long is the rubber band now as

it was at first?

General a × b = ? a × ? = p, and p ÷ a = ? ? × b = p, and p ÷ b = ?

 

4The language in the array examples shows the easiest form of array problems. A harder form is to use the terms rows and columns: The apples in the grocery window are in 3 rows and 6 columns. How many apples are in there? Both forms are valuable.

5Area involves arrays of squares that have been pushed together so that there are no gaps or overlaps, so array problems include these especially important measurement situations.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                               

7The first examples in each cell are examples of discrete things. These are easier for students and should be given

before the measurement examples.

 

No Tags

34310 total views, 24 today

  

Listing ID: 8865e125e9c45bde

Report problem

Processing your request, Please wait....