RP.2 Understand the concept of a unit rate a/b associated with a ratio a:b with b ≠ 0, and use rate language in the context of a ratio relationship.
warm-up
Pick 5 and use the key to check your work
1) There are 6 cookies for 8 students. How much of a cookie should each child receive?
2) Mrs. Franklin paid 3 boys $51 for doing yard work. How much did she pay each boy if they received the same amount?
3) Celia rode her bike 5 miles in 2 hours. What is her rate per hour? How long would it take her to ride 17 ½ miles?
2) Mrs. Franklin paid 3 boys $51 for doing yard work. How much did she pay each boy if they received the same amount?
3) Celia rode her bike 5 miles in 2 hours. What is her rate per hour? How long would it take her to ride 17 ½ miles?
mini lesson - independent work/share out/discussion
1) Wiz Khalifa is trying to decide where to send his daughter to school. Wiz Khalifa is looking for a school with a low student-teacher ratio. The Drake School has 108 students and 18 teachers. The Kendrick Lamar School has 75 students and 15 teachers. Which school has the lower student-teacher ratio?
2) The Mount Major hike starts in Alton Bay, 716 feet above sea level. The summit is 1796 feet above sea level, and it takes about 45 minutes for a typical hiker to make the climb. Find the rate at which this hiker gains altitude, in feet per minute.
2) The Mount Major hike starts in Alton Bay, 716 feet above sea level. The summit is 1796 feet above sea level, and it takes about 45 minutes for a typical hiker to make the climb. Find the rate at which this hiker gains altitude, in feet per minute.
team challenge
Mangos for Sale
A store was selling 8 mangos for $10 at the farmers market.
Keisha said, “That means we can write the ratio 10 : 8, or $1.25 per mango.” Luis said,
“I thought we had to write the ratio the other way, 8 : 10, or 0.8 mangos per dollar." Can we write different ratios for this situation? Explain why or why not.
Hippos Love Pumpkins
a. Hippos sometimes get to eat pumpkins as a special treat. If 3 hippos eat 5 pumpkins, how many pumpkins per hippo is that?
b. Lindy made 24 jelly-bread sandwiches with a 16-ounce jar of jelly. How many ounces of jelly per sandwich is that?
c. Purslane bought 350 rolls of toilet paper for the whole year. How many rolls of toilet paper per month is that?
d. In the world's longest running experiment, scientists have tried to capture tar pitch dripping on camera. In the past 86 years, 9 drops have formed. How many years per drop is that?
e. Imagine that 12 goats got into a dumpster behind a pizza parlor and ate 3 pizzas. How many goats per pizza would that be?
Riding at a Constant Speed, Assessment Variation
Lin rode a bike 20 miles in 150 minutes. If she rode at a constant speed,
a. How far did she ride in 15 minutes?
b. How long did it take her to ride 6 miles?
c. How fast did she ride in miles per hour?
d. What was her pace in minutes per mile?
A store was selling 8 mangos for $10 at the farmers market.
Keisha said, “That means we can write the ratio 10 : 8, or $1.25 per mango.” Luis said,
“I thought we had to write the ratio the other way, 8 : 10, or 0.8 mangos per dollar." Can we write different ratios for this situation? Explain why or why not.
Hippos Love Pumpkins
a. Hippos sometimes get to eat pumpkins as a special treat. If 3 hippos eat 5 pumpkins, how many pumpkins per hippo is that?
b. Lindy made 24 jelly-bread sandwiches with a 16-ounce jar of jelly. How many ounces of jelly per sandwich is that?
c. Purslane bought 350 rolls of toilet paper for the whole year. How many rolls of toilet paper per month is that?
d. In the world's longest running experiment, scientists have tried to capture tar pitch dripping on camera. In the past 86 years, 9 drops have formed. How many years per drop is that?
e. Imagine that 12 goats got into a dumpster behind a pizza parlor and ate 3 pizzas. How many goats per pizza would that be?
Riding at a Constant Speed, Assessment Variation
Lin rode a bike 20 miles in 150 minutes. If she rode at a constant speed,
a. How far did she ride in 15 minutes?
b. How long did it take her to ride 6 miles?
c. How fast did she ride in miles per hour?
d. What was her pace in minutes per mile?