Math Investigations

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Chapter 22

Part 1: For the problem in the Teacher's Edition, page 586

Students can practice their research skills by finding the results of the Boston Marathon wheelchair race. Provide students with a copy of the Problem Worksheet (PDF file).

If students are doing their own research, tell them that they can look for either the winning times for women in the wheelchair race or the winning times for men in the wheelchair race. Those who choose to research the winning times for men will also need to find the most recent winning time for women so they can answer the last question.

Make sure the students understand that a time like 1:34:22 means one hour, 34 minutes, and 22 seconds.


Men's Wheelchair Champions
Year Name Time
Time to Nearest Minute   Difference  
2000 Franz Nietlispach 1:33:32 1:34  
2001 Ernst F. Van Dyk 1:25:12 1:25 34 − 25 = 9
9 minutes
2002 Ernst F. Van Dyk 1:23:19 1:23 25 − 23 = 2
2 minutes
2003 Ernst F. Van Dyk 1:28:32 1:29 23 − 29 = −6
−6 minutes
2004 Ernst F. Van Dyk 1:18:27 1:18 29 − 18 = 11
11 minutes
Women's Wheelchair Champions
Year Name Time
Time to Nearest Minute   Difference  
2000 Jean Driscoll 2:00:52 2:01  
2001 Louise Sauvage 1:53:54 1:54 1 + 6 = 7
7 minutes
2002 Edith Hunkeler 1:45:57 1:46 54 − 46 = 8
8 minutes
2003 Christina Ripp 1:54:47 1:55 46 − 55 = −9
−9 minutes
2004 Cheri Blauwet 1:39:53 1:40 55 − 40 = 15
15 minutes

The difference between Jean Driscoll's winning time in 1990 and the winning time for women in 2004 is about 3 minutes.

Part 2: Be an Investigator

A good time to do this investigation is after Lesson 2 on comparing and ordering rational numbers.

Introducing the Investigation

Introduce the investigation by reading aloud the assignment at the top of the first page of the Description of Investigation and Student Report (PDF file), by having one of your students read aloud the assignment, or by having the students read the assignment individually.

Put the students in groups of two to four to work on the investigation.

Doing the Investigation

Make sure the students understand what a back order is by explaining that if a customer orders something that is not in stock, the item is placed on back order. The order will be filled when the stock comes in. For example, −2 1/3 bags of cement means that cement is out of stock and 21/3 bags of cement are on back order for customers.


Order for stocking cement in stores:
Susan's, Al's, Pete's, Joe's, Zelda's

Order for stocking gravel in stores::
Joe's, Pete's, Susan's, Al's, Zelda's

Student Report

The letter back to Jerry Lee gives the students an opportunity to show what they have done.

Houghton Mifflin Math Grade 6