Multiply This!Multiply This!

By Cheryl KremerBy Cheryl Kremer

June 20, 2006June 20, 2006

What is What is Multiplication?Multiplication?

United Streaming United Streaming video goes here.video goes here.

It is a great way to

count things!

What is Multiplication?What is Multiplication?When you add several sets of something, When you add several sets of something, you use multiplication.you use multiplication.

((4 sets4 sets of of 3 pencils3 pencils) 4 x 3 = 12 pencils) 4 x 3 = 12 pencils

Example: 4 students each have 3 pencils.Example: 4 students each have 3 pencils.

Why Not Add?Why Not Add?

Addition works, but it takes Addition works, but it takes longer.longer.AdditionAddition

2 + 2 + 2 + 2 + 2 = 102 + 2 + 2 + 2 + 2 = 10

MultiplicationMultiplication 2 x 5 = 102 x 5 = 10

When will I use it?When will I use it?

At SchoolAt School

At HomeAt Home

At WorkAt Work

Multiplication Multiplication at School:at School:

I was told to give 3 sheets of graph paper to each student in I was told to give 3 sheets of graph paper to each student in my class of 25.my class of 25.

How many sheets do I need?How many sheets do I need?

3 x 25 = 75 sheets of 3 x 25 = 75 sheets of paperpaper

Multiplication Multiplication at School:at School:

I bought 3 gel pens at the I bought 3 gel pens at the

student store for $.75 each.student store for $.75 each.

3 x $.75 = 3 x $.75 = $2.25$2.25

How much do I pay?How much do I pay?

$.75 $.75 $.75

Multiplication Multiplication at Home:at Home:

I had a party and wanted to give I had a party and wanted to give eacheach of my 3 friends of my 3 friends plus myselfplus myself, 3 , 3 slices of pizza. slices of pizza.

4 x 3 = 12 slices of pizza4 x 3 = 12 slices of pizzaHow many slices of pizza do I need?How many slices of pizza do I need?

X

Multiplication Multiplication at Home:at Home:

I was making a triple batch of I was making a triple batch of cookies for my friends. The recipe cookies for my friends. The recipe called for 2 cups of flour. How called for 2 cups of flour. How much flour should I use?much flour should I use?

2 cups2 cups

x =6 cups 6 cups of flourof flour3 batches3 batches

Multiplication Multiplication at Work:at Work:

My brother makes $5.00 per hour for My brother makes $5.00 per hour for doing yard work. If he works 3 hours doing yard work. If he works 3 hours each Saturday for 10 weeks, how each Saturday for 10 weeks, how much will he earn?much will he earn?

$5.00 per hour x 3 hours per week = $5.00 per hour x 3 hours per week = $15.00 per week$15.00 per week

$15.00 per week x 10 weeks = $150.00 $15.00 per week x 10 weeks = $150.00 TotalTotal

Multiplication at Work:Multiplication at Work:

My friend makes $7.00 per hour My friend makes $7.00 per hour

working at Taco Bell. working at Taco Bell.

How much will she make in 8 hours?How much will she make in 8 hours?

$7.00 x 8 = $56.00$7.00 x 8 = $56.00

Fun Fact:Fun Fact:

The The oppositeopposite of multiplication is division. of multiplication is division. When you already know the total and you When you already know the total and you

want to know how many are in each set, want to know how many are in each set, you do the opposite, divide.you do the opposite, divide.

You are having a party with 3 of your friends. If you already know how many pieces of pizza you have ( 12 pieces) and you want to know how many pieces each of you can have, you use division.

12 pieces ÷ 4 people =

3 pieces per person 

What did I learn?What did I learn?

1. What is multiplication used for?1. What is multiplication used for?To add up multiple sets of something.To add up multiple sets of something.

2. Why not add?2. Why not add?It takes longer than multiplication.It takes longer than multiplication.

3. What is the opposite of multiplication?3. What is the opposite of multiplication?DivisionDivision

4. Where can I use multiplication?4. Where can I use multiplication?At school, home, and at work.At school, home, and at work.

Works CitedWorks Cited

California Department of EducationCalifornia Department of Educationhttp://www.cde.ca.gov/be/st/ss/mthgrade3.asphttp://www.cde.ca.gov/be/st/ss/mthgrade3.aspState Content Standards for Mathematics 3rd, 4th, and 5th State Content Standards for Mathematics 3rd, 4th, and 5th

grades. grades. www.staffs.ac.uk www.staffs.ac.uk

3 pencils graphic3 pencils graphic