6th Grade Math Textbook, Fundamentals

Lesson 4-7 for exercise sets. &KDSWHU 

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Estimate each product by rounding.

1.0.93 • 0.52 2.26.1 • 0.537 3.0.016 • 0.135 4.17.3 • 0.0003 5.34.872 • 8.402

Estimate each quotient by using compatible numbers.

6.31.62 9.57 7.46.332 836.4 8.0.075 ÷ 0.23 9.6.19 0.035 10.0.094 11.4

11.Discuss and Write Explain how estimating products and quotients

with decimal numbers is the same as, or different from, the way you

estimate products and quotients with integers.

Use compatible numbers to estimate the quotient of two decimals

that are each less than 1.

• Estimate: 0.078 0.048
  You can use the division fact 8  4 2.
  8 hundredths4 hundredths 8  4  2
  So 0.078 0.048 2.


• Estimate: 0.1905 0.00617
  You can use the division fact 18  6 3.
  180 thousandths6 thousandths 180  6  30
  So 0.1905 0.00617 30.

To estimate the quotient of a decimal less than 1 and

a decimal greater than 1, find compatible numbers.

For a divisor less than 1, multiply it by the least power

of 10 that will make it a whole number.

Multiply the dividend by that same power of 10.

• To estimate 673.8 0.084, use the division fact 64  8 8.
  A dividend close to 673.8 is 640, and a divisor close
  to 0.084 is 0.08. Multiply both the dividend and
  the divisor by 100 to make the divisor a whole number.
  [(100)(640)] [(100)(0.08)] 640.00 0.08 64,000  8  8000

So 673.8 0.084 8000.

• Estimate: 0.026 41.99
  Use the division fact 28  4 7.

0.028  40

So 0.026 ÷ 41.99 0.0007.

There is more than one way to estimate a quotient. You can use different

pairs of compatible numbers.

Estimate: 24.32 4.52

24.32 4.52 20  5 4 24.32 4.52 25  5 5 24.32 4.52 24  4  6

40

0 000

0 0280

. 7
.

Think

0.1905 0.180

0.00617 0.006

Think

0.078 0.08

0.048 0.04

Remember:

To multiply a number by a power

of 10, move the decimal point to

the rightthe same number

of places as the number of zeros

in the standard form of the power.

Think

0.08(100)  8

640(100) 64,000