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Lesson 1

1. Lesson 1

1.9. Explore 5

Mathematics 20-2 M6 Lesson 1

Module 6: Proportional Reasoning

 

tip bar

The time 1:45:30 can be written in a number of different ways: 1 h 45 min 30 s; 105 min 30 s; 105:30; or 105.5 min.

 

As you have seen in this lesson, different strategies can be used to interpret and compare rates. The purpose of the comparison needs to be considered when determining what type of rate to use in a given situation. Some rates are easier to understand and visualize than others. For instance, the packing rate for moving boxes could have been represented as minutes per box, boxes per minute, or boxes per hour.

 

This is a photo of three moving boxes with packing rates written on them. The top box is labelled 0.095 boxes per minute. The middle box is labelled 5.7 boxes per hour. The bottom box is 10.55 minutes per box. A man with a dolly is standing behind the boxes.

Brand X Pictures/Thinkstock

 

It is hard to visualize 0.095 of a moving box. In this situation, it would be more appropriate to compare the packing rate as the number of minutes it takes to pack one box or the number of boxes that can be packed in one hour.

 

Self-Check 5

 

This is a photo of fingers texting on a cellphone keyboard.

iStockphoto/Thinkstock

Did You Know?
Did you know that there is a Guinness World Record for the fastest time to write a text message (SMS) on a touchscreen mobile phone? The record is determined by timing how long it takes competitors to write a specific text message. On August 22, 2010, Melissa Thompson wrote “the razor-toothed piranhas of the genera Serrasalmus and Pygocentrus are the most ferocious freshwater fish in the world. In reality they seldom attack a human” on her mobile phone in an amazing 25.94 s. That is a finger-burning rate of about one word per second! Has anyone beat her texting rate? Do an Internet search to find out.

 



  1. Trinity and her friends are trying to determine who among them can text the fastest. They each typed a text message into their cellphones. The following table shows their results.

    Trinity

    3 words/12 s

    Josh

    4 words/18 s

    Juanita

    1 word/5 s


    1. From this information, are you able to determine who can text the fastest? Justify your decision. Answer

    2. What factors could influence the texting rate? Identify whether each factor would increase or decrease the texting rate. Answer

textbook
  1. Complete “Check Your Understanding” question 2 on page 459 of your textbook. Answer

  2. Complete “Practising” question 6 on page 459 of your textbook. Answer