<< Chapter < Page Chapter >> Page >
By the end of this section, you will be able to:
  • Use multiplication notation
  • Model multiplication of whole numbers
  • Multiply whole numbers
  • Translate word phrases to math notation
  • Multiply whole numbers in applications

Before you get started, take this readiness quiz.

  1. Add: 1,683 + 479 .
    If you missed this problem, review Add Whole Numbers .
  2. Subtract: 605 321 .
    If you missed this problem, review Subtract Whole Numbers .

Use multiplication notation

Suppose you were asked to count all these pennies shown in [link] .

An image of 3 horizontal rows of pennies, each row containing 8 pennies.

Would you count the pennies individually? Or would you count the number of pennies in each row and add that number 3 times.

8 + 8 + 8

Multiplication is a way to represent repeated addition. So instead of adding 8 three times, we could write a multiplication expression.

3 × 8

We call each number being multiplied a factor and the result the product    . We read 3 × 8 as three times eight , and the result as the product of three and eight .

There are several symbols that represent multiplication. These include the symbol × as well as the dot, · , and parentheses ( ).

Operation symbols for multiplication

To describe multiplication, we can use symbols and words.

Operation Notation Expression Read as Result
Multiplication ×
·
( )
3 × 8
3 · 8
3 ( 8 )
three times eight the product of 3 and 8

Translate from math notation to words:

  1. 7 × 6
  2. 12 · 14
  3. 6 ( 13 )

Solution

  • We read this as seven times six or the product of seven and six .
  • We read this as twelve times fourteen or the product of twelve and fourteen .
  • We read this as six times thirteen or the product of six and thirteen .
Got questions? Get instant answers now!
Got questions? Get instant answers now!

Translate from math notation to words:

  1. 8 × 7
  2. 18 · 11
  1. eight times seven ; the product of eight and seven
  2. eighteen times eleven ; the product of eighteen and eleven
Got questions? Get instant answers now!

Translate from math notation to words:

  1. ( 13 ) ( 7 )
  2. 5 ( 16 )
  1. thirteen times seven ; the product of thirteen and seven
  2. five times sixteen; the product of five and sixteen
Got questions? Get instant answers now!

Model multiplication of whole numbers

There are many ways to model multiplication. Unlike in the previous sections where we used base-10 blocks, here we will use counters to help us understand the meaning of multiplication. A counter is any object that can be used for counting. We will use round blue counters.

Model: 3 × 8 .

Solution

To model the product 3 × 8 , we’ll start with a row of 8 counters.
An image of a horizontal row of 8 counters.

The other factor is 3 , so we’ll make 3 rows of 8 counters.
An image of 3 horizontal rows of counters, each row containing 8 counters.

Now we can count the result. There are 24 counters in all.

3 × 8 = 24

If you look at the counters sideways, you’ll see that we could have also made 8 rows of 3 counters. The product would have been the same. We’ll get back to this idea later.

Got questions? Get instant answers now!
Got questions? Get instant answers now!

Model each multiplication: 4 × 6 .


No Alt Text

Got questions? Get instant answers now!

Model each multiplication: 5 × 7 .


No Alt Text

Got questions? Get instant answers now!

Multiply whole numbers

In order to multiply without using models, you need to know all the one digit multiplication facts. Make sure you know them fluently before proceeding in this section.

[link] shows the multiplication facts. Each box shows the product of the number down the left column and the number across the top row. If you are unsure about a product, model it. It is important that you memorize any number facts you do not already know so you will be ready to multiply larger numbers.

Questions & Answers

what is mutation
Janga Reply
what is a cell
Sifune Reply
how is urine form
Sifune
what is antagonism?
mahase Reply
classification of plants, gymnosperm features.
Linsy Reply
what is the features of gymnosperm
Linsy
how many types of solid did we have
Samuel Reply
what is an ionic bond
Samuel
What is Atoms
Daprince Reply
what is fallopian tube
Merolyn
what is bladder
Merolyn
what's bulbourethral gland
Eduek Reply
urine is formed in the nephron of the renal medulla in the kidney. It starts from filtration, then selective reabsorption and finally secretion
onuoha Reply
State the evolution relation and relevance between endoplasmic reticulum and cytoskeleton as it relates to cell.
Jeremiah
what is heart
Konadu Reply
how is urine formed in human
Konadu
how is urine formed in human
Rahma
what is the diference between a cavity and a canal
Pelagie Reply
what is the causative agent of malaria
Diamond
malaria is caused by an insect called mosquito.
Naomi
Malaria is cause by female anopheles mosquito
Isaac
Malaria is caused by plasmodium Female anopheles mosquitoe is d carrier
Olalekan
a canal is more needed in a root but a cavity is a bad effect
Commander
what are pathogens
Don Reply
In biology, a pathogen (Greek: πάθος pathos "suffering", "passion" and -γενής -genēs "producer of") in the oldest and broadest sense, is anything that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ. The term pathogen came into use in the 1880s.[1][2
Zainab
A virus
Commander
Definition of respiration
Muhsin Reply
respiration is the process in which we breath in oxygen and breath out carbon dioxide
Achor
how are lungs work
Commander
where does digestion begins
Achiri Reply
in the mouth
EZEKIEL
what are the functions of follicle stimulating harmones?
Rashima Reply
stimulates the follicle to release the mature ovum into the oviduct
Davonte
what are the functions of Endocrine and pituitary gland
Chinaza
endocrine secrete hormone and regulate body process
Achor
while pituitary gland is an example of endocrine system and it's found in the Brain
Achor
what's biology?
Egbodo Reply
Biology is the study of living organisms, divided into many specialized field that cover their morphology, physiology,anatomy, behaviour,origin and distribution.
Lisah
biology is the study of life.
Alfreda
Biology is the study of how living organisms live and survive in a specific environment
Sifune
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply
Practice Key Terms 1

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Prealgebra. OpenStax CNX. Jul 15, 2016 Download for free at http://legacy.cnx.org/content/col11756/1.9
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Prealgebra' conversation and receive update notifications?

Ask