Lesson 4

Estimating with Multiplication

Est. Class Sessions: 2

Daily Practice and Problems

Teacher Notes
X

TIMS Bit

  1. Review with students how to use the class clock to time thirty seconds. Have students work in pairs or groups, so that they can time each other.
    Discuss with students what it means to collect data, so that their estimates in Question C will be accurate and the answers will be similar from group to group. For example, the length of the name should be held fixed. The class should decide if the writers will write the first name, last name, or full name.
    Remind students of experiments such as Bouncing Ball when they collected data and used three trials to minimize experimental error. Discuss with students how they can use multiple trials in this data collection. If students work in a group of four, one student can time the other three students and then average the numbers. Or, one partner can time another partner who repeats the task three or more times.
  2. 30 seconds is 1/2 of a minute.
  3. Estimates will vary based on the data collected, but students should multiply the average time by 2 to get the number for one minute, then by 5 for the number for five minutes.

Use this DPP item to prepare students for a similar activity in Lesson 5 Hour Walk.

M. How Many in Five Minutes?

  1. Collect data on the number of times a fourth-grader can write his or her name in 30 seconds. Work with a group or a partner. Have one person use a watch or a class clock to time 30 seconds while the others write their names. How can you be sure the data represents the fourth-graders in your class?
  2. 30 seconds is what fraction of a minute?
  3. Use your data to estimate how many times a fourth-grader can write his or her name in five minutes. How did you estimate?