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420 18. 73 21. 430 18. 380 16. Warm Up Divide. Round answers to the nearest tenth. 1. 2. 3. 4. 23.3. 3.5. 23.9. 23.8. Vocabulary. Rate Unit Rate Unit Price Estimate. A rate is a comparison of two quantities measured in different units.
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420 18 73 21 430 18 380 16 Warm Up Divide. Round answers to the nearest tenth. 1.2. 3.4. 23.3 3.5 23.9 23.8
Vocabulary Rate Unit Rate Unit Price Estimate
A rate is a comparison of two quantities measured in different units. For example, the phrase “90 miles per 3 hours” can be written... 90 3 ...as a ratio like this, Ratio: 90 miles 3 hours Rate: ...or as a rate, like this
90 3 The ratio can also be simplified by dividing: Unit rates are rates in which the second quantity is 1. 90 3 30 1 = 30 miles, 1 hour unit rate: or 30 mi/h
30 words minute 1 2 30 words • 2 minute • 2 1 2 Class Example Geoff can type 30 words in half a minute. How many words can he type in 1 minute? Write as a rate. Multiply to find words per minute. 60 words 1 minute = Geoff can type 60 words in one minute.
Partner Practice Penelope can type 90 words in 2 minutes. How many words can she type in 1 minute? 90 words 2 minutes Write a rate. Divide to find words per minute. 90 words ÷ 2 2 minutes ÷ 2 45 words 1 minute = Penelope can type 45 words in one minute.
Individual Practice A piece of gold with a volume of 0.5 cubic meters weighs 9650 kilograms. What is the density of gold? 9650 kg 0.5 m3 Write the rate. 9650 kg • 2 0.5 m3 • 2 Multiply to find kilograms per 1 m3. 19,300 kg 1 m3 Gold has a density of 19,300 kg/m3.
To estimate is to find a value that is close to the actual value, but not necessarily the true value.
320 feet 8 seconds 313 feet 8 seconds 40 feet 1 second Partner Practice Estimate the unit rate. 313 Is not divisible by 8, so choose a number close to 313 that is divisible by 8. 313 feet in 8 seconds Divide to find feet per second. 313 feet to 8 seconds is approximately 40 feet per second.
595 players 85 soccer balls 583 players 85 soccer balls 7 players 1 soccer ball Individual Practice Estimate each unit rate. 583 soccer players to 85 soccer balls. Choose a number close to 583 that is divisible by 85. Divide to find players per soccer ball. 583 soccer players to 85 soccer balls is approximately 7 players per soccer ball.
Class Practice Pens can be purchased in a 5-pack for $1.95 or a 15-pack for $6.20. Which pack has the lower unit price? Set up proportions for both situations. price for package number of pens $1.95 5 = = $0.39 Divide the price by the number of pens. price for package number of pens $6.20 15 = $0.41 Compare to determine your answer. The 5-pack for $1.95 has the lower unit price.
price for jar number of ounces price for jar number of ounces Partner Practice Jamie can buy a 15 oz jar of peanut butter for $2.19 or a 20 oz jar for $2.78. Which jar has the lower unit price? $2.19 15 = $0.15 $2.78 20 = $0.14 The 20 oz jar for $2.78 has the lower unit price.