25.1 and 25.2Percents, Decimals and

Fractionsp. 556 and 558

Introduction: Quick Review Objective: 1. To write ratios as percents and express parts of a whole area as percents 2. Learn how to estimate and find a percent of a number Remember: when multiplying decimals numbers, move the decimal to the RIGHT for each power of 10 (i.e. 100 - two powers of ten, move the decimal over TWO to the right: .2 = .20 = 20%)

Glossary

Glossary

•Fraction to Percent: divide, move decimal to the right two spots (i.e. 1/5 = .20 = 20%)

•Decimal to Percent: multiply by 100, move decimal to the right two spots (i.e. .20 = 20%)

•Percent to Fraction: write as a fraction over 100 - simplify (i.e. 20% = 20/100 = 1/5)

•Percent to Decimal: divide by 100, move decimal to the left two spots (i.e. 20% = .20)

•Fraction to Percent: divide, move decimal to the right two spots (i.e. 1/5 = .20 = 20%)

•Decimal to Percent: multiply by 100, move decimal to the right two spots (i.e. .20 = 20%)

•Percent to Fraction: write as a fraction over 100 - simplify (i.e. 20% = 20/100 = 1/5)

•Percent to Decimal: divide by 100, move decimal to the left two spots (i.e. 20% = .20)

•Fraction to Percent: divide, move decimal to the right two spots (i.e. 1/5 = .20 = 20%)

•Decimal to Percent: multiply by 100, move decimal to the right two spots (i.e. .20 = 20%)

•Percent to Fraction: write as a fraction over 100 - simplify (i.e. 20% = 20/100 = 1/5)

•Percent to Decimal: divide by 100, move decimal to the left two spots (i.e. 20% = .20)

25.3Estimate and Find

Percent of a Numberp. 562

Introduction: Quick Review Objective: Learn how to estimate and find a percent of a number

Glossary

Guided Instruction:Example 1: Finding the percent of a number• 60% of 25

•

•

•Josh played in ____ games.

Tip:

_____15% of _____

Our Work (write 15% as a fraction or a decimal and multiply it with the total: 15/100 x $___

OR .15 x $____):

Tip:

_____Tip:

_____15% of _____

Our Work (write 15% as a fraction or a decimal and multiply it with the total: 15/100 x $___

OR .15 x $____):

15% of _____ Our Work (write 15% as a fraction or a

decimal and multiply it with the total: 15/100 x $___

OR .15 x $____):

25.4Discount and Sales Tax

p. 568

Introduction: Quick Review Objective: to learn how to solve problems involving discounts and sales tax Vocab: •discount= amount subtracted from the regular price•SALE PRICE = regular price - discount!•sales tax= percent of the cost of an item

Glossary

Guided Instruction:Example 1: Discount - Volleyball set, $32 (25% off)• 32 x .25 = _________

• SALE PRICE = regular price - discount

•

• Discount = _________ and Sale Price = __________

Example 3: Sales Tax - Table tennis, $119 (5% sales tax)

• 119 x .05 = ___________

• She paid ___________ in sales tax.

25.6Simple Interest

p. 538

Introduction: Quick Review Objective: Learn how to find simple interest

Vocab: •principal= original amount put into a bank account

•simple interest= fixed percent of the principal paid yearly (formula: I = prt ... I = interest, p = principal, r = interest rate per year, t = time in years)

Glossary

Guided Instruction:Example 1: Finding the simple interest ($500, 6%, 2 years)• I = prt

•

•

•Katrina will earn ________ in interest.

RECAP: Match the vocab word with its definition • I = interest, p = principal, r = interest

rate per year, t = time in years

• amount subtracted from the regular price

• original amount put into a bank account

• percent of the cost of an item

• regular price - discount

• fixed percent of the principal paid yearly

• principal

• discount

• SALE PRICE

• sales tax

• simple interest

• rate

• I = prt