1

STANDARD 1.2

A tenth of a tenth?

A tenth of three tenths?

Finding the pattern: A tenth of…

Six tenths of six tenths?

Four tenths of five tenths?

PROBLEM 2

PROBLEM 1

END SHOW

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2

1.2 Add, subtract, multiply and divide rational numbers and take positive rational numbers to whole-number powers

1.2 Sumar, restar, multiplicar y dividir números racionales y elevar números positivos racionales a potencias de enteros.

GRADE 7: Number Sense

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3STANDARD 1.2

110

110

110

1100

= = .011

10 (.1)(.1)= .01

then

1 tenth of 1 tenth is 1 hundredth

110

of1

10

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4STANDARD 1.2

110

410

410

4100

= = .041

10 (.1)(.4)= .04

then

1 tenth of 4 tenths are 4 hundredths

110

of4

10

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5STANDARD 1.2

410

510

510

20100

= = .204

10 (.4)(.5)= .20

then

4 tenths of 5 tenths are 20 hundredths

410

of5

10

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6STANDARD 1.2

610

610

610

36100

= = .366

10 (.6)(.6)= .36

then

6 tenths of 6 tenths are 36 hundredths

610

of 610

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7

STANDARD 1.2

110

1100

= = .011

10 (.1)(.1)= .01

1100

11000

= = .0011

10 (.1)(.01)= .001

11000

110000

= = .00011

10 (.1)(.001)= .0001

110000

1100000

= = .000011

10 (.1)(.0001)= .00001

11

110

= = .11

10 (.1)(1)= . 1

Can you find the pattern, when you multiply a decimal by a tenth?

A TENTH OF …

You move the decimal point one place to the left inserting a zero if necessary.

What would happen when you multiply by a hundredth? By a thousandth?

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8

STANDARD 1.2

A THOUSANDTH is a tenth of a hundredth.What is a thousandth?

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9

STANDARD 1.2

1.7x 3

15

Decimal placesDecimal placesDecimal places in the result.

101

15x

1.7.3

Decimal placesDecimal placesDecimal places in the result.

112

15x

1.7.03

Decimal placesDecimal placesDecimal places in the result.

1230

15x

1.7.003

Decimal placesDecimal placesDecimal places in the result.

13400

31

5110

=1710 = 5.1(3)(1.7) =

310

51100

=1710 = .51(.3)(1.7)=

3100

511000

=1710 = .051(.03)(1.7)=

31000

5110000

=1710 = .0051(.003)(1.7)=

Three TENTHS of 1.7

Three HUNDREDTHS of 1.7

Three THOUSANDTHS of 1.7

Can you figure out the rule?

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10

STANDARD 1.2

Penny

=$ .01

1 cent

1¢

$1100

A hundredth of a dollar.

Remember!

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11

STANDARD 1.2

John had 65 cents and he spent a fifth of this money buying a candy. What amount did he spend in hundredths of a dollar?

=$ .65 65¢ 100

= .2 1 5

65100

15

(.2)(.65)= .130

03x

.65 .2

Decimal placesDecimal placesDecimal places in the result.

2131

So, he spent 130 thousandths of a dollar or 13 hundredths of a dollar.

=.13

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12

STANDARD 1.2

The beach is at 5.6 miles from the main road. A store is located at half of this distance, north the beach. How many miles away is the store from the beach?

= .5 1 2

02 8x

5.6.5

Decimal placesDecimal placesDecimal places in the result.

112

Half of the distance:

So, the store is located at 2.8 miles from the beach.

Two and eight tenths of a mile.

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