Practice your math. Click on the link, click on fourth grade, practice the activities under multilplication.

http://www.ixl.com

http://www.multiplication.com

http://www.learnzillion.com/lessons

http://www.ixl.com

http://www.multiplication.com

http://www.learnzillion.com/lessons

## DISTRIBUTIVE PROPERTY

Use the examples above to solve the following problems:

3 x 15

3x (10 +5)

(3 x 10) + (3 X5)

30 + 15 + 45

7 x 16

5 x 14

9 x 19

3 x 17

3 x 15

3x (10 +5)

(3 x 10) + (3 X5)

30 + 15 + 45

7 x 16

5 x 14

9 x 19

3 x 17

## MULTIPLYING USING EXPANDED FORM

## MULTIPLYING (HALVING AND DOUBLING)

18 X 50 1. CUT 18 IN HALF 18 DIVIDED BY 2 EQUALS 9

2. MULTIPLY 9 X 50 = 450

3. DOUBLE THE PRODUCT 450 + 450 = 900

TRY THESE:

14 X 30

16 X 20

12 X 60

2. MULTIPLY 9 X 50 = 450

3. DOUBLE THE PRODUCT 450 + 450 = 900

TRY THESE:

14 X 30

16 X 20

12 X 60

## COMMUTATIVE PROPERTY OF MULTIPLICATOIN

THE ORDER OF THE FACTORS DOES NOT MATTER. 3 X 4 = 4 X 3 4 X 2 X 8 = 2 X 8 X 4

5 X 17 X 20 HOW CAN I ARRANGE THESE FACTORS TO MAKE IT POSSIBLE TO USE MENTAL MATH

5 X 20 X 17 5 X 20 = 100

100 X 17 = ( 1 X 17 AND ADD THE ZEROS) 1700

TRY THESE:

4 X 19 X 24

20 X 13 X 5

5 X 17 X 20 HOW CAN I ARRANGE THESE FACTORS TO MAKE IT POSSIBLE TO USE MENTAL MATH

5 X 20 X 17 5 X 20 = 100

100 X 17 = ( 1 X 17 AND ADD THE ZEROS) 1700

TRY THESE:

4 X 19 X 24

20 X 13 X 5

## USING AREA MODELS AND PARTIAL PRODUCTS

## USING PARTIAL PRODUCTS TO MULTIPLY

Pick a strategy to find the product:

8 x 25 x 30= 17 x 36 = 5 X 195 =

18 x 20 = 5 x 18 x 20 = 4 x 36 x 25 =

35 = 7 x 5 35 is 7 times as many as 7 or 35 is 5 times as many as 7

6 x 4 = 24 6 times as many as 4 is 24 or 4 times as many as 6 is 24

Try these:

__Remember:__times means multiply

is means =

30 = 5 x 6 _____ is ______times as many as __________

3 x 6 = 18 _______times as many as __________ is _________

4x5 = 20 _____times as many as ________ is ___________

Write the equation

5 times as many as 7 is 35

14 is 2 times as many as 7

21 is 7 times as many as 3

10 times as many as 5 is 50

Multiplication as Comparison 4 x 7 = 28 can be read as a comparison between the numbers in the equation. It helps to remember that the equal sign really means "is the same as."

- 4 x 7 is the same as 28.
- 28 is the same as 4 x 7.
- 28 is the same as 4 sets of 7.
- 28 is 4 times as many as 7.

- 7 x 4 is the same as 28.
- 28 is the same as 7 x 4.
- 28 is the same as 7 sets of 4.
- 28 is 7 times as many as 4.

Check this out:

http://learnzillion.com/lessons/2746-solve-multiplicative-comparison-word-problems-by-using-a-multiplication-sentence

http://learnzillion.com/lessons/2745-solve-multiplicative-comparison-word-problems-by-using-bar-models

## PLACE VALUE

The value of a digit is 10 times the value of the digit to its right.

333 300 + 30 + 3

The 3 in the tens place is 10 times larger than the 3 in the ones place (30 is ten times larger than 3)

The 3 in the hundreds place is 10 times larger than the 3 in the tens place (300 is ten times larger than 30

The 3 in the hundreds place is 100 times larger than the 3 in the ones place ( 300 is 100 times larger than 3)

333 300 + 30 + 3

The 3 in the tens place is 10 times larger than the 3 in the ones place (30 is ten times larger than 3)

The 3 in the hundreds place is 10 times larger than the 3 in the tens place (300 is ten times larger than 30

The 3 in the hundreds place is 100 times larger than the 3 in the ones place ( 300 is 100 times larger than 3)