This problem solving activity has a measurement focus.
Sally the Snail crawls 2cm each minute.
She needs to rest at each dot for 5 minutes.
She wants to take the shortest time to reach a plant.
Which path should she take?
This problem explores time in minutes and distance in centimetres.
The calculations involve single digit addition and multiplication, and afford opportunities for students to apply a range of strategies.
Sally the Snail crawls 2cm each minute. She needs to rest at each dot for 5 minutes. She wants to take the shortest time to reach a plant. Which path should she take?
(see the Copymaster for a picture of the paths)
Get the students to create their own snail-path problem for others to solve. The may decide to vary the speed that Sally moves. The solutions will dependent on the problems posed and the numbers used.
Path 1: The snail has to travel 2 + 4 + 6 + 2 = 14 cm which takes 7 minutes. She has 3 rest stops which take 15 minutes. So the total time for the trip is 22 minutes.
Path 2: The snail has to travel 2 + 2 + 2 + 2 + 2 + 2 = 12 cm which takes 6 minutes. She has 5 rest stops which take 25 minutes. So the total time for the trip is 31 minutes.
Path 3: The snail has to travel 4 + 6 + 2 + 4 = 16 cm which takes 8 minutes. She has 3 rest stops which take 15 minutes. So the total time for the trip is 23 minutes.
Path 4: The snail has to travel 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 = 18 cm which takes 9 minutes. She has 8 rest stops which take 40 minutes. So the total time for the trip is 49 minutes.
Some students may add another 5 minutes for the final dot on each path but at that point Sally is already at the plant.
The path that takes the shortest time is path 1.
Printed from https://nzmaths.co.nz/resource/snails at 10:12am on the 8th May 2024