1

STANDARDS 1.3, 1.6

Problem 1

Problems 3

Problem 2

PERCENT OF INCREASE OR DECREASE

Problem 4

Problems 6

Problem 5

Problems 7END SHOW

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2

1.3 Convert fractions to decimals and percents and use these representations in estimations, computations and applications.

1.3 Convertir fracciones a decimales y porcentajes y usar estas representaciones en estimaciones, cálculos y aplicaciones.

GRADE 7: Number Sense

1.6 Calculate the percentage of increase and decrease of a quantity.

1.6 Calcular el porcentaje de incremento y decremento de una cantidad.

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3

% of CHANGE = CHANGE

ORIGINAL

NEW PRICE=$.60

What is the percent of change between the original price and the new?

ORIGINAL PRICE=$.40

Original Price is $.40 and New Price is $.60. Find the percent of increase or decrease:

STANDARDS 1.3, 1.6PRESENTATION CREATED BY SIMON PEREZ. All rights reserved

4

% of CHANGE = CHANGE

ORIGINAL

=$.20

% of CHANGE= .60 –.40

.40

= .20

.40

.20.40 05

20-00

(100%)

= .5

(.5)

Now convert it to PERCENT:

= 50 %

What is the ratio that compares the change in price with the original price?

So, the price was INCREASED 50%

$.40

ORIGINAL PRICE

$.60 – $.40

CHANGE IN PRICE

Original Price is $.40 and New Price is $.60. Find the percent of increase or decrease:

STANDARDS 1.3, 1.6PRESENTATION CREATED BY SIMON PEREZ. All rights reserved

5

% of CHANGE = CHANGE

ORIGINAL

NEW PRICE=$.22

What is the percent of change between the original price and the new?

ORIGINAL PRICE=$.66

Original Price is $.66 and New Price is $.22. Find the percent of increase or decrease:

STANDARDS 1.3, 1.6PRESENTATION CREATED BY SIMON PEREZ. All rights reserved

6

% of CHANGE = CHANGE

ORIGINAL

= -.44

% of CHANGE= .22 –.66 .66

= -.44 .66

.44.66 06

396-44 0

6

39-44

(100%)

=0.6644

6600

-0.662

300

Now convert it to PERCENT:

= -0.6644

6600

%= -6623

or

What is the ratio that compares the change in price with the original price?

So, the price was DECREASED approximately 66.7%

$.22 – $.66

CHANGE IN PRICE

-66.7%

6

....

2222 = -0.66

2300

Original Price is $.66 and New Price is $.22. Find the percent of increase or decrease:

STANDARDS 1.3, 1.6PRESENTATION CREATED BY SIMON PEREZ. All rights reserved

7

% of CHANGE = CHANGE

ORIGINAL

NEW PRICE=$.59

What is the percent of change between the original price and the new?

ORIGINAL PRICE=$.39

Original Price is $.39 and New Price is $.59. Find the percent of increase or decrease:

STANDARDS 1.3, 1.6PRESENTATION CREATED BY SIMON PEREZ. All rights reserved

8

% of CHANGE = CHANGE

ORIGINAL

=$.20

% of CHANGE= .59 –.39 .39

= .20

.39

.20.39 05

19 5-50

1

39-11

(100%)

=0.5111

3900

0.5111

3900

Now convert it to PERCENT:

=0.5111

3900

%= 511139

or

What is the ratio that compares the change in price with the original price?

So, the price was INCREASED approximately 51.3%

$.39

ORIGINAL PRICE

$.59 – $.39

CHANGE IN PRICE

51.3%

Original Price is $.39 and New Price is $.59. Find the percent of increase or decrease:

STANDARDS 1.3, 1.6PRESENTATION CREATED BY SIMON PEREZ. All rights reserved

9

% of CHANGE = CHANGE

ORIGINAL

NEW PRICE=$140

ORIGINAL PRICE=$120

Original Price is $120 and New Price is $140. Find the percent of increase or decrease:

Change in price = $140 – $120

= $20

% of CHANGE = 140 – 120

120

= 20

120

1 6 0 6-4

What is the ratio that compares the change in price with the original price?

....

22

16

=

036-4

=0.164

600

....

22

= 0.162

300

= 0.162

300

(100%) 0.162

300%= 16

23

or 16.7%

So, the price was INCREASED approximately 16.7%

16

Convert to percent:

STANDARDS 1.3, 1.6PRESENTATION CREATED BY SIMON PEREZ. All rights reserved

10

% of CHANGE = CHANGE

ORIGINAL

NEW NUMBER= 20

ORIGINAL NUMBER= 60

The number of deer in the zoo changed from 60 t0 20. What was the percent of change?

Change in number = 20– 60

= 40

% of CHANGE = 20 – 60

60

= - 40

60

2 3 018-2

What is the ratio that compares the change in deer before and after?

....

2020

2 3

= -

018-

2

=0.662

300

= -.662

300

(100%) -.662

300%= -66

23

or -66.7%

So, the number of deer was DECREASED approximately 66.7%

66

Convert to percent:

STANDARDS 1.3, 1.6PRESENTATION CREATED BY SIMON PEREZ. All rights reserved

11

% of CHANGE = CHANGE

ORIGINAL

NEW NUMBER= 200

ORIGINAL NUMBER= 80

The number of horses in a ranch changed from 80 to 200. What was the percent of change?

Change in number = 200– 80

= 120

% of CHANGE = 200 – 80

80

= 120

80

What is the ratio that compares the change in horses before and after?

32

=

So, the number of horses was INCREASED approximately 150%

STANDARDS 1.3, 1.6

....

4040

3 21

210

5

100

=1.5

(100%)(1.5)

Now convert to PERCENT:

= 150 %PRESENTATION CREATED BY SIMON PEREZ. All rights reserved

12

% of CHANGE = CHANGE

ORIGINAL

Juniors in 2004 = 450

Juniors in 1979 = 150

In a High School there were 150 juniors in 1979, now in 2004 there are 450. What was the percent of change?

Change in number = 450 – 150

= 300

% of CHANGE = 450 – 150

150

= 300

150

What is the ratio that compares the change in juniors from one year to the other?

21

=

So, the number of juniors was INCREASED 200%

STANDARDS 1.3, 1.6

....

150150

= 2

(100%)(2)

Now convert to PERCENT:

= 200 %PRESENTATION CREATED BY SIMON PEREZ. All rights reserved