Sally Snail crawls at the rate of five inches per minute. She leaves her home, crawling along a straight line, at 3:00 PM.

1. 1. How far away from home is she at 3:01?
   2. How far away from home is she at 3:04?
2. 1. At what time will she be 30 inches from home?
   2. At what time will she be 32 inches from home?
3. 1. At 3:00, as we know, Sally is at home. How long will it take her to crawl 15 inches from home?
   2. At 3:15, Sally passes her friend Tilly’s home. How long will it take her to crawl 15 inches from Tilly’s home?
4. Draw a graph showing Sally’s distance from home at each minute from 3:00 to 3:15.
5. Answer the following ‘true’ or ‘false’. Be prepared to justify your answer.
   1. When Sally first leaves her house, it will take her 3 minutes to crawl 15 inches. When she is way past Tilly’s house, it will still take her 3 minutes to crawl 15 inches.
   2. It takes Sally twice as long to crawl 20 inches as it does for her to crawl 10 inches.
   3. It takes Sally twice as long to crawl 300 inches as it does for her to crawl 150 inches.
   4. It takes Sally three times as long to crawl 20 inches as it does for her to crawl 6 inches.
   5. Sally will crawl three times as far in 24 minutes as she will crawl in 8 minutes.
   6. Sally will crawl four times as far in 40 minutes as she will crawl in 10 minutes.
6. According to this little story,
   1. Does Sally ever get tired of crawling?
   2. Does she slow down or speed up?
   3. Does she stop?
7. Which of problems 1a - 6c could not be answered if Sally ever changed speed during her trip?

1. 1. 5 in
   2. 20 in
2. 1. at 3:06
   2. at 3:06:24
3. 1. 3 min
   2. 3 min
4.  

   

5. 1. True
   2. True
   3. True
   4. True
   5. True
   6. True
6. 1. No
   2. No
   3. No
7. If we assume that for the first minute her rate was 5 in/min, but might change after that, then we can still answer problem 1a, but all others are unanswerable.

1. 1. 5 in/min×1 min = 5 in
   2. 5 in/min×4 min = 20 in
2. 1. 30 in ÷ 5 in/min = 6 min; at 3:06
   2. 32 in ÷ 5 in/min = 6 min 24 sec; at 3:06:24
3. 1. 15 in÷5 in/min = 3 min
   2. 15 in÷ 5 in/min = 3 min
4.  

   

5. 1. True. If Sally’s Snail rate of crawl is constant, she will crawl 15 inches in 3 minutes after she past Tilly’s house, and she will crawl 15 inches in 3 minutes when she first leave her home.
   2. True. Because her rate of travel is constant, it will take her 4 minutes to crawl 20 inches, and it’ll take her 2 minutes to crawl 10 inches.
   3. True. Similarly to 5b.
   4. True. Similarly to 5b.
   5. True. Similarly to 5b.
   6. True. Similarly to 5b.
6. 1. No
   2. No
   3. No
7. If we assume that for the first minute her rate was 5 in/min, but might change after that, then we can still answer problem 1a, but all others are unanswerable.