The Great Hamster Race

1
The Great Hamster Race
Kirby and Shelby each have a hamster. As part of
a project they decided to have the hamsters race
through a 1.50 m maze. After the first minute
Kirby's hamster was 35 cm from the starting point
and Shelby's hamster was 25 cm from the starting
point. Because hamsters don't really understand
racing, after the second minute both hamsters
were 30 cm from the starting point. At the end of
three minutes Kirby's hamster was 65 cm from the
starting point and Shelby's hamster was 55 cm
from the starting point. At the end of four
minutes both hamsters were 60 cm from the
starting point. If the race kept going the same
way, who's hamster finally won the race and how
many minutes did it take for the hamster to win?
2
What is the question we are asked?
Kirby and Shelby each have a hamster. As part of
a project they decided to have the hamsters race
through a 1.50 m maze. After the first minute
Kirby's hamster was 35 cm from the starting point
and Shelby's hamster was 25 cm from the starting
point. Because hamsters don't really understand
racing, after the second minute both hamsters
were 30 cm from the starting point. At the end of
three minutes Kirby's hamster was 65 cm from the
starting point and Shelby's hamster was 55 cm
from the starting point. At the end of four
minutes both hamsters were 60 cm from the
starting point. If the race kept going the same
way,
whose hamster finally won the race and how many
minutes did it take for the hamster to win?
3
What information do we have?
Kirby and Shelby each have a hamster. As part of
a project they decided to have the hamsters race
through a 1.50 m maze. After the first minute
Kirby's hamster was 35 cm from the starting point
and Shelby's hamster was 25 cm from the starting
point. Because hamsters don't really understand
racing, after the second minute both hamsters
were 30 cm from the starting point. At the end of
three minutes Kirby's hamster was 65 cm from the
starting point and Shelby's hamster was 55 cm
from the starting point. At the end of four
minutes both hamsters were 60 cm from the
starting point. If the race kept going the same
way, who's hamster finally won the race and how
many minutes did it take for the hamster to win?
4
What information do we have?

• 2 hamsters
• 1.5 m (150 cm) maze to race in
• Hamster 1 is 35 cm, 30 cm, 65 cm, 60 cm from
  start after each of the first 4 minutes
• Hamster 2 is 25 cm, 30 cm, 55 cm, 60 cm from
  start after each of the first 4 minutes
• There is a pattern to find (If the race kept
  going the same way . . .)

5
What information are we looking for?

• Where each hamster is after the next minute, and
  the one after that, and so on
• When each hamster passes the 150 cm (1.5 m) mark
  in the maze
• Which hamster crossed first
• The number of minutes it took for the winning
  hamster to get to the 150 cm mark for the first
  time.

6
After 1 minute . . .
Shelbys Hamster
Kirbys Hamster
7
After 2 minutes . . .
Shelbys Hamster
Kirbys Hamster
8
After 3 minutes . . .
Shelbys Hamster
Kirbys Hamster
9
After 4 minutes . . .
Shelbys Hamster
Kirbys Hamster
10
After 1 minute . . .
Kirbys Hamster
Shelbys Hamster
Make a chart of how far the hamsters go. The
minutes are across the top and the two hamsters
down the side.
11
After 2 minutes . . .
Kirbys Hamster
Shelbys Hamster
12
After 3 minutes . . .
Kirbys Hamster
Shelbys Hamster
13
After 4 minutes . . .
Kirbys Hamster
Shelbys Hamster
14
Look for a pattern to complete the chart

• You could go up by 30 every second minute

15
Look for a pattern to complete the chart

• You could go up by 30 every second minute
• You could add 35 one minute and subtract 5 the
  next for Kirbys hamster and 25 one minute and
  add five the next for Shelbys
• You could go 5 above the even minute for Kirbys
  hamster and 5 below for Shelbys hamster

16
Find the Answer to the Problem in the chart

• After 10 minutes both hamsters are at the finish
  line 1.5 m from the start.

17
Find the Answer to the Problem in the chart

• After 10 minutes both hamsters are at the finish
  line 150 cm (1.5 m) from the start.
• But after only 9 minutes, Kirbys hamster was
  already past the finish line at 155 cm from the
  start.
• Then Kirbys hamster won, crossing the finish
  line after only 9 minutes.