bellwork

BELLWORKSolve the following problem without using a calculator.

In the past seven years, the MSA Fundraising Committee has earned $2358.45; $3056.23; $2515.01; $1875.00; $3978.99; $3219.62; and $3008.84. How much more did the MSA Fundraising Committee make than the committee at Lakewood Ranch High School which only made $19,651.13 in those seven years?

Multiplying & Dividing Decimals

UNIT 1.2 NOTES

MULTIPLY DECIMALSDecimals are multiplied as if they were whole numbers. (It is not necessary to line up the decimal points.) Do you remember how to place the decimal point in your final answer?

4.5 x 7.1 = 31.958.789 x 4 = 35.156.08 x .09 = .0072

MULTIPLY DECIMALSThe decimal point in the answer is then found by using the following steps.

STEP 1: Count the total number of digits to the right of the decimal point in each of the numbers being multiplied.

STEP 2: In the answer, count from right to left the number of places found in STEP 1 AND WRITE THE DECIMAL POINT. It may be necessary to attach zeros to the left of the answer in order to correctly place the decimal point.

4.5 x 7.1 = 31.95 1 + 1 = 28.789 x 4 = 35.156 3 + 0 = 3.08 x .09 = .0072 2 + 2 = 4

EXAMPLESa) 8.34 x 4.2 b) .032 x .07

a) 8.34 x 4.2

166833360

35.028

b) .032 x .07

.00224

2 decimals1 decimal

3 decimals

3 decimals2 decimals

5 decimals

YOUR TURNa) 6.7 x 4.32 b) .086 x .05

Answersa) 28.944b) .0043

GROSS PAYGross pay = Number of hours worked x Pay per hour

Find the gross pay of a SUBWAY employee working 31.5 hours at a rate of $8.65 per hour.

Answer: $272.48

DIVIDE DECIMALSDividing terms: Quotient, Dividend, Divisor

3 )21.937.31

Quotient

Divisor

Dividend

Place a decimal point directly above the dividend’s decimal point.

DIVIDE DECIMALS

5 )14.2 2.84

Example 1: Sometimes it is necessary to place zeros after the decimal point in the dividend. Why?

Does attaching zeros after the decimal point change the value of the dividend?

No.

5 )14.20

DIVIDE DECIMALS

3 )4.70001.5666

Example 2: A remainder of 0 might not be obtained even though extra zeros are placed after the dividend.

Round to the nearest thousandth by carrying out the division to four places and then rounding to three places.

DIVIDE DECIMALS

.3 )27.692.0

Example 3: To divide by a decimal, first convert the divisor to a whole number.

Round to the nearest thousandth by carrying out the division to four places and then rounding to three places.

. .

YOUR TURNa) 17.6 ÷ .25 b) 5 ÷ .42

Answersa) 70.4b) 11.905