Lesson 3

Using Ratios

Est. Class Sessions: 2–3

Daily Practice and Problems

Teacher Notes
X

TIMS Task

This DPP item can be used as a Problem of the Week. Calculators should be available. Have students share the strategies they used to solve the problems. Possible strategies include:

  1. $1.75 ÷ .25 = 7 quarters; 7 × 15 minutes = 1 hour and 45 minutes; 1 hr. 45 min. after 1:50 is 3:35.
  2. 3:35 to 4:30 is 55 minutes; 55 minutes is about 4 more intervals of 15 minutes, so she will need 4 more quarters or $1.00.
    1. 2 hours and 40 min.
    2. 2 hrs. × 60 min. per hour = 120 min.,
      120 + 40 = 160 min.
    3. 160 min. × 60 sec. per hour = 9600 sec.

Students will connect seconds to minutes and numbers to hours in the Distance vs. Time lesson.

L. Time Is Money

It is 1:50 PM when Nila's mother parks the car near Nila's ballet lesson. The parking meter costs 25 cents for each 15 minutes. It takes only quarters. Nila's mother has $1.75 in quarters.

  1. If she uses all her quarters, what time will she need to return to her car?
  2. If she wants to stay until 4:30, how much more money will she need? Show or tell how you know.
  3. How long is it from 1:50 to 4:30?
    1. Give your answer in hours and minutes.
    2. GIve your answer in minutes.
    3. Give your answer in seconds.