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Math Coach Amy
Amy Ferguson Moncure

7th Grade Math · Unit 2

Patterns with
Negative Powers of 10

See how powers of 10 keep the same pattern when the exponent becomes negative.

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What to Remember

Down one exponent, divide by 10

Start at a power of 10 you know. Each time the exponent decreases by 1, divide the value by 10.

10² = 100, so 10¹ = 10, and 10⁰ = 1.

10 to the zero is 1

10⁰ = 1. That is the bridge from whole numbers into decimals.

The next step down divides 1 by 10.

A negative exponent is not a negative number

The next power after 10⁰ is 10⁻¹.

1 ÷ 10 = 0.1, so 10⁻¹ = 0.1. The value stays positive.

Keep going the same way

10⁻¹ = 0.1

0.1 ÷ 10 = 0.01, so 10⁻² = 0.01.

Every new negative step is another division by 10. The value gets smaller, but it does not turn negative.

Level 1

Easy

One step at a time. The exponent goes down by 1, and the value is divided by 10.

Example
The pattern is 10¹ = 10, then 10⁰ = 1. Describe the pattern, then find the next power and its value.

Each time the exponent decreases by 1, divide the value by 10.

The next exponent is 0 − 1 = −1.

1 ÷ 10 = 0.1

10⁻¹ = 0.1

The value is positive. A negative exponent does not make a negative number.

Answer: 10⁻¹ = 0.1

1
Continue one step. 10³ = 1,000, then 10² = 100. What power and value come next?
Show Answer

Each time the exponent decreases by 1, divide the value by 10.

100 ÷ 10 = 10

10¹ = 10

Answer: 10¹ = 10

2
Continue one step. 10⁴ = 10,000. What power and value come next?
Show Answer

Each time the exponent decreases by 1, divide the value by 10.

10,000 ÷ 10 = 1,000

10³ = 1,000

Answer: 10³ = 1,000

3
Start at 10² = 100. Write the next three powers and their values.
Show Answer

Each time the exponent decreases by 1, divide the value by 10.

100 ÷ 10 = 10

10¹ = 10

10 ÷ 10 = 1

10⁰ = 1

1 ÷ 10 = 0.1

10⁻¹ = 0.1

Answer: 10¹ = 10, 10⁰ = 1, 10⁻¹ = 0.1

4
The values decrease: 100, 10, 1, ___. What is the blank, and which power of 10 is it?
Show Answer

Each value is the one before it divided by 10.

1 ÷ 10 = 0.1

100 is 10², 10 is 10¹, and 1 is 10⁰.

The next power is 10⁻¹.

Answer: 0.1, which is 10⁻¹

5
The exponents decrease: 2, 1, 0, ___. What is the next exponent? Is the value negative?
Show Answer

The list is 2, 1, 0, then the blank.

The next exponent is 0 − 1 = −1.

Start from 10⁰ = 1.

1 ÷ 10 = 0.1

0.1 is positive. The exponent is negative, and the value is not.

Answer: Exponent −1, and the value 0.1 is positive

6
Start at 10¹ = 10. Divide by 10 twice. What power and value do you land on?
Show Answer

Each time the exponent decreases by 1, divide the value by 10.

10 ÷ 10 = 1

10⁰ = 1

1 ÷ 10 = 0.1

10⁻¹ = 0.1

Answer: 10⁻¹ = 0.1

7
Fill in both blanks. 10¹ = 10
10⁰ = ___
10⁻¹ = ___
Show Answer

Each time the exponent decreases by 1, divide the value by 10.

10 ÷ 10 = 1

10⁰ = 1

1 ÷ 10 = 0.1

10⁻¹ = 0.1

Answer: 10⁰ = 1 and 10⁻¹ = 0.1

Level 2

Medium

Follow the pattern several steps into the negative exponents.

Example
The values are 10, 1, and 0.1. Write the power of 10 for each value, and explain the pattern.

Each value is the one before it divided by 10, so each exponent is 1 less.

10 = 10¹

1 = 10⁰

0.1 = 10⁻¹

The pattern crosses from whole numbers into a positive decimal.

Answer: 10¹, 10⁰, and 10⁻¹

1
Start at 10⁰ = 1. Write the next three powers and their values.
Show Answer

Each time the exponent decreases by 1, divide the value by 10.

1 ÷ 10 = 0.1

10⁻¹ = 0.1

0.1 ÷ 10 = 0.01

10⁻² = 0.01

0.01 ÷ 10 = 0.001

10⁻³ = 0.001

Answer: 10⁻¹ = 0.1, 10⁻² = 0.01, 10⁻³ = 0.001

2
Fill in the missing power and value.
10² = 100
___
10⁰ = 1
10⁻¹ = 0.1
Show Answer

The exponents decrease by 1: 2, then 1, then 0, then −1.

The missing exponent is 1.

100 ÷ 10 = 10, so 10¹ = 10.

Answer: 10¹ = 10

3
Start at 10³ = 1,000. How many times do you divide by 10 to reach 10⁻¹? What is the value?
Show Answer

Each time the exponent decreases by 1, divide the value by 10.

1,000 ÷ 10 = 100

10² = 100

100 ÷ 10 = 10

10¹ = 10

10 ÷ 10 = 1

10⁰ = 1

1 ÷ 10 = 0.1

10⁻¹ = 0.1

That is 4 divisions.

Answer: 4 times, and 10⁻¹ = 0.1

4
The values are 1, 0.1, 0.01, and 0.001. Write the power of 10 for each value.
Show Answer

1 = 10⁰

Divide by 10: 0.1 = 10⁻¹

Divide by 10 again: 0.01 = 10⁻²

Divide by 10 again: 0.001 = 10⁻³

Answer: 10⁰, 10⁻¹, 10⁻², 10⁻³

5
Use the pattern to explain why 10⁻² is smaller than 10⁻¹.
Show Answer

10⁻¹ = 0.1

One more step down divides by 10 again.

0.1 ÷ 10 = 0.01

10⁻² = 0.01

0.01 is smaller than 0.1. The more negative exponent is the smaller value.

Answer: 10⁻² = 0.01, which is smaller than 0.1

6
Start at 10¹ = 10. Write the next four powers and their values.
Show Answer

Each time the exponent decreases by 1, divide the value by 10.

10 ÷ 10 = 1

10⁰ = 1

1 ÷ 10 = 0.1

10⁻¹ = 0.1

0.1 ÷ 10 = 0.01

10⁻² = 0.01

0.01 ÷ 10 = 0.001

10⁻³ = 0.001

Answer: 10⁰ = 1, 10⁻¹ = 0.1, 10⁻² = 0.01, 10⁻³ = 0.001

7
Copy the table and fill in the blank.
PowerValue
10¹10
10⁰1
10⁻¹0.1
10⁻²___
Show Answer

Each row divides the value above it by 10.

0.1 ÷ 10 = 0.01

PowerValue
10¹10
10⁰1
10⁻¹0.1
10⁻²0.01

Answer: 10⁻² = 0.01

8
Start at 10⁻¹ = 0.1. Go two steps down. Write both powers and values.
Show Answer

Each time the exponent decreases by 1, divide the value by 10.

0.1 ÷ 10 = 0.01

10⁻² = 0.01

0.01 ÷ 10 = 0.001

10⁻³ = 0.001

Answer: 10⁻² = 0.01 and 10⁻³ = 0.001

9
Use the rule, starting from 10⁰ = 1, to find 10⁻³. Show each division.
Show Answer

Each time the exponent decreases by 1, divide the value by 10.

1 ÷ 10 = 0.1

10⁻¹ = 0.1

0.1 ÷ 10 = 0.01

10⁻² = 0.01

0.01 ÷ 10 = 0.001

10⁻³ = 0.001

Answer: 10⁻³ = 0.001

Level 3

Hard

Explain the pattern, and use it to reach smaller powers of 10.

Example
A student says a negative exponent makes a negative value. Use 10¹ = 10 and the pattern to show why 10⁻¹ is not negative.

Each time the exponent decreases by 1, divide the value by 10.

10 ÷ 10 = 1

10⁰ = 1

1 ÷ 10 = 0.1

10⁻¹ = 0.1

0.1 is greater than zero. The exponent changed sign. The value did not.

Answer: 10⁻¹ = 0.1, which is positive

1
Start at 10³ = 1,000. Show every step down to 10⁻³.
Show Answer

Each time the exponent decreases by 1, divide the value by 10.

1,000 ÷ 10 = 100

10² = 100

100 ÷ 10 = 10

10¹ = 10

10 ÷ 10 = 1

10⁰ = 1

1 ÷ 10 = 0.1

10⁻¹ = 0.1

0.1 ÷ 10 = 0.01

10⁻² = 0.01

0.01 ÷ 10 = 0.001

10⁻³ = 0.001

Answer: 10⁻³ = 0.001

2
Explain why 10⁻⁴ is not a negative number. Give its value from the pattern.
Show Answer

Each time the exponent decreases by 1, divide the value by 10.

1 ÷ 10 = 0.1

10⁻¹ = 0.1

0.1 ÷ 10 = 0.01

10⁻² = 0.01

0.01 ÷ 10 = 0.001

10⁻³ = 0.001

0.001 ÷ 10 = 0.0001

10⁻⁴ = 0.0001

Every step divides a positive number by 10.

The result stays positive. Only the exponent is negative.

Answer: 10⁻⁴ = 0.0001, which is positive

3
Start at 10⁰ = 1. How many times do you divide by 10 to reach 10⁻⁴? What is the value?
Show Answer

Each time the exponent decreases by 1, divide the value by 10.

1 ÷ 10 = 0.1

10⁻¹ = 0.1

0.1 ÷ 10 = 0.01

10⁻² = 0.01

0.01 ÷ 10 = 0.001

10⁻³ = 0.001

0.001 ÷ 10 = 0.0001

10⁻⁴ = 0.0001

That is 4 divisions. The decimal point moved 4 places.

Answer: 4 times, and 10⁻⁴ = 0.0001

4
10⁻⁴ = 0.0001. Use the pattern to find 10⁻⁵ and 10⁻⁶.
Show Answer

Each time the exponent decreases by 1, divide the value by 10.

0.0001 ÷ 10 = 0.00001

10⁻⁵ = 0.00001

0.00001 ÷ 10 = 0.000001

10⁻⁶ = 0.000001

Answer: 10⁻⁵ = 0.00001 and 10⁻⁶ = 0.000001

5
Use the pattern to order 10⁻¹, 10⁻³, and 10⁰ from least to greatest.
Show Answer

Each step down divides by 10, so the value gets smaller.

10⁰ = 1

10⁻¹ = 0.1

10⁻³ = 0.001

0.001 is smallest and 1 is largest.

10⁻³ < 10⁻¹ < 10⁰

Answer: 10⁻³ < 10⁻¹ < 10⁰

6
Start at 10² = 100. How many divisions by 10 reach 0.00001? What exponent is that?
Show Answer

Each time the exponent decreases by 1, divide the value by 10.

100 ÷ 10 = 10

10¹ = 10

10 ÷ 10 = 1

10⁰ = 1

1 ÷ 10 = 0.1

10⁻¹ = 0.1

0.1 ÷ 10 = 0.01

10⁻² = 0.01

0.01 ÷ 10 = 0.001

10⁻³ = 0.001

0.001 ÷ 10 = 0.0001

10⁻⁴ = 0.0001

0.0001 ÷ 10 = 0.00001

10⁻⁵ = 0.00001

That is 7 divisions. The exponent is 2 − 7 = −5.

Answer: 7 divisions, and the power is 10⁻⁵

7
Write every power and value from 10² down to 10⁻⁴.
Show Answer
PowerValue
10²100
10¹10
10⁰1
10⁻¹0.1
10⁻²0.01
10⁻³0.001
10⁻⁴0.0001

Answer: From 10² = 100 down to 10⁻⁴ = 0.0001

8
Write the rule in one sentence. Then start at 10⁻² = 0.01 and find 10⁻⁵.
Show Answer

Each time the exponent decreases by 1, divide the value by 10.

0.01 ÷ 10 = 0.001

10⁻³ = 0.001

0.001 ÷ 10 = 0.0001

10⁻⁴ = 0.0001

0.0001 ÷ 10 = 0.00001

10⁻⁵ = 0.00001

Answer: 10⁻⁵ = 0.00001

9
Start at 10⁵ = 100,000. Keep dividing by 10 until the value is 0.001. List every power you land on, including the start.
Show Answer

Each time the exponent decreases by 1, divide the value by 10.

100,000 ÷ 10 = 10,000

10⁴ = 10,000

10,000 ÷ 10 = 1,000

10³ = 1,000

1,000 ÷ 10 = 100

10² = 100

100 ÷ 10 = 10

10¹ = 10

10 ÷ 10 = 1

10⁰ = 1

1 ÷ 10 = 0.1

10⁻¹ = 0.1

0.1 ÷ 10 = 0.01

10⁻² = 0.01

0.01 ÷ 10 = 0.001

10⁻³ = 0.001

Answer: 10⁵ down to 10⁻³ = 0.001

Extra

Find the Exponent

10 to a positive exponent is 1 followed by that many zeros.

Example
What number can replace “?”
10? = 10,000,000

10,000,000 is 1 followed by 7 zeros.

That is 10⁷.

The exponent is 7.

Answer: 7

1
What number can replace “?”
10? = 10
Show Answer

10 is 1 followed by 1 zero.

That is 10¹.

The exponent is 1.

Answer: 1

2
What number can replace “?”
10? = 100
Show Answer

100 is 1 followed by 2 zeros.

That is 10².

The exponent is 2.

Answer: 2

3
What number can replace “?”
10? = 1,000
Show Answer

1,000 is 1 followed by 3 zeros.

That is 10³.

The exponent is 3.

Answer: 3

4
What number can replace “?”
10? = 100,000
Show Answer

100,000 is 1 followed by 5 zeros.

That is 10⁵.

The exponent is 5.

Answer: 5

5
What number can replace “?”
10? = 1,000,000
Show Answer

1,000,000 is 1 followed by 6 zeros.

That is 10⁶.

The exponent is 6.

Answer: 6

6
What number can replace “?”
10? = 1,000,000,000
Show Answer

1,000,000,000 is 1 followed by 9 zeros.

That is 10⁹.

The exponent is 9.

Answer: 9

Extra

Multiply by One Tenth

10 to a negative exponent is one tenth multiplied that many times.

Example
How many times must 110 be multiplied to equal 10⁻⁴?

A negative exponent counts factors of 110.

10⁻⁴ = 110⁴.

110 is multiplied 4 times.

Answer: 4 times

1
How many times must 110 be multiplied to equal 10⁻²?
Show Answer

A negative exponent counts factors of 110.

10⁻² = 110².

110 is multiplied 2 times.

Answer: 2 times

2
How many times must 110 be multiplied to equal 10⁻³?
Show Answer

A negative exponent counts factors of 110.

10⁻³ = 110³.

110 is multiplied 3 times.

Answer: 3 times

3
How many times must 110 be multiplied to equal 10⁻⁵?
Show Answer

A negative exponent counts factors of 110.

10⁻⁵ = 110⁵.

110 is multiplied 5 times.

Answer: 5 times

4
How many times must 110 be multiplied to equal 10⁻⁶?
Show Answer

A negative exponent counts factors of 110.

10⁻⁶ = 110⁶.

110 is multiplied 6 times.

Answer: 6 times

5
How many times must 110 be multiplied to equal 10⁻⁷?
Show Answer

A negative exponent counts factors of 110.

10⁻⁷ = 110⁷.

110 is multiplied 7 times.

Answer: 7 times

6
How many times must 110 be multiplied to equal 10⁻⁹?
Show Answer

A negative exponent counts factors of 110.

10⁻⁹ = 110⁹.

110 is multiplied 9 times.

Answer: 9 times

Extra

Small Decimals

Match the decimal to a negative power of 10, then count the factors of one tenth.

Example
How many times must 110 be multiplied to equal 0.001?

0.001 = 10⁻³.

The exponent is −3, so 110 is a factor 3 times.

Answer: 3 times

1
How many times must 110 be multiplied to equal 0.1?
Show Answer

0.1 = 10⁻¹.

The exponent is −1, so 110 is a factor 1 time.

Answer: 1 time

2
How many times must 110 be multiplied to equal 0.01?
Show Answer

0.01 = 10⁻².

The exponent is −2, so 110 is a factor 2 times.

Answer: 2 times

3
How many times must 110 be multiplied to equal 0.00001?
Show Answer

0.00001 = 10⁻⁵.

The exponent is −5, so 110 is a factor 5 times.

Answer: 5 times

4
How many times must 110 be multiplied to equal 0.000001?
Show Answer

0.000001 = 10⁻⁶.

The exponent is −6, so 110 is a factor 6 times.

Answer: 6 times

5
How many times must 110 be multiplied to equal 0.0000001?
Show Answer

0.0000001 = 10⁻⁷.

The exponent is −7, so 110 is a factor 7 times.

Answer: 7 times

6
How many times must 110 be multiplied to equal 0.000000001?
Show Answer

0.000000001 = 10⁻⁹.

The exponent is −9, so 110 is a factor 9 times.

Answer: 9 times

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