Notes 7.2B Decimal Operations

Adding Decimals

*Line the decimals up!*Line the decimals up!

EX:EX: 2.3452.345

+ + 13.41 13.41

Answer:Answer: 15.75515.755

Rewrite:

Subtracting Decimals

*Line up the decimals!*Line up the decimals!

EX:EX: 11.42811.428

+ + 8.67 8.67

Answer:Answer: 2.7582.758

Rewrite:

Multiplying Decimals

*Put the number with most digits on top and line up *Put the number with most digits on top and line up LAST numbersLAST numbers

Move the decimal back at the endMove the decimal back at the end

EX:EX: 2.3452.345 x x 13.4 13.4

Answer:Answer: 31.42331.423

Rewrite:

Dividing Decimals

*Kick the ball to the wall*Kick the ball to the wallDo the same in the hallDo the same in the hall& Throw it on the roof& Throw it on the roof

EX:EX: 25.725.7 ÷ ÷ 3.1 3.1

Answer:Answer: 8.2908.290

Rewrite:

7.2B Fraction Operations

Adding Fractions

*we must first find a *we must first find a COMMON COMMON DENOMINATORDENOMINATOR

• Then add the numerators

EX:

2 ¾ + 5 ½

Rewrite (w/ common denominators):

Subtracting Fractions

*we must first find a COMMON COMMON DENOMINATORDENOMINATOR

• Then subtract the numerators

EX:

4 1/3 - 3 ½

Rewrite (w/ common denominators):

Multiplying Fractions

• Multiply numerator times numerator to get our numerator

• And multiply denominator times denominator to get our denominator

Mixed Numbers:

13

23

X

13

X 83 = 8

9

2Need to make an improper fraction then multiply

Improper Fraction – bigger numerator than denominator

Dividing Fractions• If dividing fractions KKeep the first fraction FFlip

the second (reciprocal) and CChange the sign (KFC)(KFC)

13

÷ 25 = 1

3X 5

2reciprocal

= 56

Dividing Mixed Numbers:14

÷ 13 = 1

473 =

328

2 ÷

14

X 37 =

Practice QuestionsOn your own sheet of notebook paper please

complete the following problems:

p 293 #20-28 (odds) p 304 #39-47(odds)

p 316 #15-19(odds), 21-25(odds)

Book Practice

On a separate sheet of paper please do the following questions in your book:

(and please show your work)

Page 137 #25-30Page 137 #25-30

Page 150 #26-30Page 150 #26-30

Page 713 #16-20Page 713 #16-20