Do Now 12/11/13 Take out HW from last night. Take out HW from last night. Text p.152, #6-24 evens, 27, 31, & 32 Text p.152, #6-24 evens, 27, 31, & 32 Copy HW in your planner. Copy HW in your planner. Text p. 156, #16-36 multiples of 4; & #43 Text p. 156, #16-36 multiples of 4; & #43 Text p. 160, #6-30 evens, 39, 40, 44, & 45 Text p. 160, #6-30 evens, 39, 40, 44, & 45 In your journal, write 2 ratios that are equivalent to the given ratios. In your journal, write 2 ratios that are equivalent to the given ratios.

Write 2 fractions that are equivalent to the given fraction.

Homework Text p.152, #6-24 evens, 27, 31, & 32 6) 18 minutes / 1 pound 6) 18 minutes / 1 pound 8) the 64 ounce container 8) the 64 ounce container 10) $115 per feet² 10) $115 per feet² 12) 13 songs per CD 12) 13 songs per CD 14) 54 words per minute 14) 54 words per minute 16) $2.16 per pound 16) $2.16 per pound 18) 11 m per s 18) 11 m per s 20) 16,000 km per hour 20) 16,000 km per hour 22) 800 minutes for $62.99 is the better buy 22) 800 minutes for $62.99 is the better buy 24) $3.55, $3.70; $24.80/8 yds is the better buy 27) 289, 328, 609; France, Poland, Germany 31) D 32) 5 cuts at a rate of 36 seconds per cut

Objective SWBAT identify and write proportions SWBAT identify and write proportions

RATE – a fraction in which the numerator and the denominator have different units of measure. RATIO- uses division to compare two quantities of the SAME MEASURE.

Proportion- an equation that states that two ratios/rates are equivalent. Section 4.2 “Identifying and Writing Proportions” “a is to b as c is to d”

If two ratios are equivalent, they are said to be PROPORTIONAL or PROPORTIONATE. Determine whether the ratios are proportional Proportional because 2/3 is equal to 2/3. Not proportional because 1/3 is not equal to 3/10.

Determine whether the ratios are proportional Not proportional because 7/8 is not equal to 7/12. Not proportional because 9/10 is not equal to 9/20. Proportional because 2/7 is equal to 2/7. Proportional because 3/2 is equal to 3/2.

Solving a Proportion Solve a proportion by finding the value of the variable. One way to solve a proportion is to write both fractions with the same denominator (think of equivalent fractions). Method #1

Solve the Following Proportions: = = = = = = x = 9 x = 4 y = 30

Solving Equations with Rates A punch recipe calls for 4 cups of orange juice. The recipe will serve 8 people. You are making punch for a party of 32 people. How many cups of orange juice do you need? A punch recipe calls for 4 cups of orange juice. The recipe will serve 8 people. You are making punch for a party of 32 people. How many cups of orange juice do you need? =

Cross Products A CROSS PRODUCT is the product of the numerator of one ratio and the denominator of the other ratio in a proportion. If, then Method #2 Section 4.3 “Solving Proportions”

Solve the Proportion If, then Divide both sides by 33

Write original proportion = x 6 Solve the proportion = 8 x615 Cross products property Simplify. 120 = 6x Divide each side by = x =8 x615 a 29 = Cross products property 21 · 29 = 7 a 609 = 7a Simplify Divide both sides by = a 87 = a Solve the proportion a 29 = Write original proportion.

The ship model kits sold at a hobby store have a scale of 1 ft : 600 ft. A completed model of the Queen Elizabeth II is 1.6 feet long. Estimate the actual length of the Queen Elizabeth II. The ship model kits sold at a hobby store have a scale of 1 ft : 600 ft. A completed model of the Queen Elizabeth II is 1.6 feet long. Estimate the actual length of the Queen Elizabeth II. Write and solve a proportion to find the length g of the Queen Elizabeth II. =1.6 g 1600 Cross products property g = 960 Simplify. 1 · g = 600 · 1.6 SOLUTION The actual length of the Queen Elizabeth II is about 960 feet.

Density is the ratio of a substance’s mass to its volume. The density of ice is 0.92 g/mL. What is the mass of 3 mL of ice?. Density is the ratio of a substance’s mass to its volume. The density of ice is 0.92 g/mL. What is the mass of 3 mL of ice?. Write and solve a proportion to find the mass of 3 mL of ice. = x 3 mL 3 mL 0.92 g 0.92 g 1 mL Cross products property x = 2.76 g Simplify. 1 · x = 3 · 0.92 SOLUTION The mass of 3 mL of ice is 2.76 grams.

NJASK7 Prep Text p. 156, #16-36 multiples of 4; & #43 Text p. 156, #16-36 multiples of 4; & #43 Text p. 160, #6-30 evens, 39, 40, 44, & 45 Text p. 160, #6-30 evens, 39, 40, 44, & 45 Homework