Converting Fractions to Decimals Two methods 1 Building

Converting Fractions to Decimals Two methods: 1. Building a fraction to a base ten number 2. Dividing numerator by denominator

Building up the fraction to a base ten number: x . 5. 20 1. 75

8/3 : Repeating Decimal = Put a bar over the first number(s) that repeats And drop the rest.

Mixed Fraction to a Mixed Decimal Whole numbers are to the left of the fraction And to the left of the decimal numbers; Convert fractional part to decimal by Dividing

Section Understanding Percent

Percent, %, means per hundred. The percent number is that number compared to a total of 100. Example: For every $100 invested, you received $6 in return; the interest rate is 6 %

What is the percentage for the following: 386/100 386% 1/100 1% . 07/100 . 07%

WHAT ARE THE RULES TO CHANGE % TO A DECIMAL? EX: 82% � Drop the % symbol 82 � Perform the operation the symbol represents - Divide by 100 - move decimal 2 places. 82 � What is the clue word? Per � - per hundred means divide by 100

the decimal 0. 47 (100%) = point two places to the right – (multiply by 100) � Move the % symbol at the end of the number 47 n. Add 47%

Remember - 47% is 47 out of every 100. A ratio is a comparison BUT You may not have 47 items. For every 100 total items, there is 47. If there were 10 total items, you would have 4. 7 items

� Percent to fraction � Drop the symbol � Write the percent number over 100 � reduce � 75% � 75/100 � 3/4

Example: 225% Rewrite % symbol as 1/100 225 1 x __1_ = 100 Simplify (reduce fraction) 225 100 2 25/100 = 2 1/4

Example % % Change to improper fraction Change symbol to fraction Reduce

Memorize the following equivalents 25% ¼ 50% ½ 75% ¾ 33 1/3% 1/3 66 2/3% 2/3 10% 1/10

Fraction to Percent Can you easily change the denominator to equal 100?

If denominator cannot be changed easily to 100, find decimal number first. 16. 67% Rounded to the nearest Hundredth of a percent

ANOTHER METHOD – FRACTION TO PERCENT: Write a proportion Cross multiply Divide by 8 n = 87. 5% 7*100 = 8 n 700 = 8 n 8 8

Changing a fraction to a percent containing a fraction: Stop the division after two steps

� Translating Equation a Percent Problem into an

� What �N �N � Find �N �N is 5% of 19. 00? =. 05 x 19. 00 =. 95 0. 6% of 400 =. 006 x 400 = 3. 6 35% of what is 60? . 35 x N = 60 /. 35 N = 1714. 2

� “What” becomes n � “Is” becomes = � Percent numbers become decimals � “of” means multiplication

EXAMPLE 90 is what percent of 20? 90 = p x 20 =4. 5 * 100% = 450% 4. 5 = n

Identify the Parts of the Percent Proportion The base, b, is always multiplied by the rate. In, 16% of 370, 370 is the base. The amount, a, is always by itself on one side of the equation. In “What percent of 18 is 4. 5? ”, 4. 5 is the amount.

A, amount Base = b R= percent Rate A = b (R) When solving for percent, change decimal to percent

Cross multiply and then divide By the variable’s coefficient Ex: Find 260 % of 40 Reduce fraction and cross multiply A(10)=40( 26) A = 4 * 26 A = 104

WHAT PERCENT OF 4000 IS 160? 400 p = 16* 100 4 %