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EOG Review Notes for Your Prep Book Grade (1). Jan 27, 2014 Monday. Factors and Multiples. Common Factor: is a number that is a factor of two or more numbers. Greatest Common Factor (GCF): the largest factor of two or more numbers
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Factors and Multiples • Common Factor: is a number that is a factor of two or more numbers. • Greatest Common Factor (GCF): the largest factor of two or more numbers • Least Common Multiple (LCM): the smallest multiple of two or more whole numbers
Greatest Common Factor: There are three ways to find the GCF: *Ladder Method *Factor Towers *Prime Factorization Ladder Method: • Find the GCF of 12 and 18 12 18 2 6 9 2 x 3 = 6 which is the GCF 3 2 3
Factor Tower Example find the GCF of 14 and 21 14 21 1 14 1 21 2 7 2 3 3 7 4 4 5 5 6 6 7 2 7 3 8 8 9 9 The factors for 14 are (1,2,7,14) The factors for 21 are (1,3,7,21) The GCF is 7
Prime Factorization: 8 32 2 4 4 8 2 2 2 2 2 4 2 2 8 : 2 x 2 x 2 32: 2 x 2 x 2 x 2 x 2 2 x 2 x 2 = 8
Do using factor tower: • 8,14 • 21,27 Do using ladder method: • 35, 49 • 18, 81 Do using the Prime factorization • 30,60 • 8,32
Prime and Composite • Product: an answer to a multiplication problem……ex) 7x8= 56 product • Factor: a number that is multiplied by another to give a product……ex) 7 x 8 = 56 factor 3. Prime Number: a number that has only two factors, itself and one. Ex) 2,3,5,7,11,13,17,19....
Prime and Composite: • Composite number: a number that has more than two factors. ex) 4,6,8,9,10,12,14,15 • The number 1: is neither prime nor a composite number • Prime Factorization: A way to write a composite number as the product of prime numbers. ex) 2 x 2 x 3 = 12 or 2² x 3 = 12
Tell the product and factor of each examples: • 7 x 9 = 63 2. 4 x 5 = 20 3. 11 x 7 = 77 Tell which numbers are prime ,composite ,or neither: • 25 2. 1 3. 13 4. 51 5. 61 Give the prime factorization of each problem: 1. 28 2. 36 3. 40 4. 200 5. 69
Least Common Multiple: There are three ways to find the LCM: *Ladder Method *Listing *Prime Factorization Ladder Method: • Find the LCM of 12 and 18 12 18 2 6 9 3 x 2 x 2 x 3 =12 3 2 3
Listing Example find the LCM of 14 and 7 14 7 1 14 1 7 2 28 2 14 3 42 3 21 4 56 4 28 5 70 5 35 6 84 6 42 7 98 7 49 8 112 8 56 9 126 9 63 The multiples for 14 are (14,28,42,56,70,84,98,112,126……..) The multiples for 7 are (7,14,21,28,35,42,49,56,63………..) The common multiples (14,28) The LCM is 14
Prime Factorization: 8 32 2 4 4 8 2 2 2 2 2 4 2 2 8 : 2 x 2 x 2 32: 2 x 2 x 2 x 2 x 2 2 x 2 x 2 = 8 x 2 x 2 = 32
Do using Listing: • 8,14 • 21,27 Do using ladder method: • 35, 49 • 18, 81 Do using the Prime factorization • 30,60 • 8,32
Ratio • Ratio: is a comparison of two quantities by division. • Ratios can be written in 3 different ways: 2 to 6 = 1 to 3 2:6 = 1:3 2/6 = 1/3 3. Make sure you put the ratio in simplest form by finding the GCF of the two numbers.
Ratio Examples: 1. Give the ratio of blue circles to purple triangles. (All three ways) 5 to 3 5:3 5/3
Example 2 of Ratio: Give the ratio of smiley faces to stars. (In all three ways). 4 to 6 = 2 to 3 4:6 = 2:3 4/6 = 2/3
Example 3: • Divide 28 cans of soda into two groups so the ratio is 3 to 4. • First add 3 +4 = 7 • 1/7 = ?/28 multiply the top and bottom by 4 • The take ¾ and multiply the top and bottom by 4 and get 21/16.
Examples for you to do: • A class has 6 boys and 15 girls. What is the ratio of boys to girls? (all three ways) • You have two triangles, four squares, and six circles on the board. Write the ratio of squares to total shapes. (all three ways) • Divide 33 photos into groups so the ratio is 4 to 7.
Rates: Vocabulary Words: • Fraction – a number that represents part of a whole or part of a set. • Ratio – a comparison of two quantities by division. • Rate – a ratio comparing two quantities with different kinds of units. • Unit rate – a rate that is simplified so that it has a denominator of 1.
Example 1) Desiree typed a 15 character text message in 5 seconds. Write the unit rate. Example 2) Samantha picked 45 oranges in 5 minutes. Write the unit rate. Example 3) The Australian Dragon fly can travel 18 miles in 30 minutes. How far can the dragonfly travel in 1 minute?
Unit price: is the cost per unit. To write a price as a unit price, divide the numerator and the denominator of the rate by the denominator. Example: It cost $36 for 4 movie tickets. What is the price per ticket? ÷ = $9 per ticket
Practice • John scored 44 points in 4 quarters. What did he score in each quarter? • Molly shot 20 basket in 4 minutes. Nico shot 42 baskets in 6 minutes. How many more baskets did Nico shoot per minute? • Theo’s mom bought an eight-pack of Juice boxes at the sore for $4. What was the price per juice box.