25.1 and 25.2 Percents, Decimals and Fractions p. 556 and 558 Introduction: Quick Review Objective:...
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Transcript of 25.1 and 25.2 Percents, Decimals and Fractions p. 556 and 558 Introduction: Quick Review Objective:...
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