Stepping Out

Many students will need a number line to solve the problem, though others may be able to use skip counting in combination with systematic recording.
For example, Kangaroo’s trip might be modelled as:

Clip-on pegs might be used on a number line to record which stepping stones Kangaroo landed on.
The solution might be recorded as:
5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60 12 numbers, 12 jumps
More powerful reasoning might be 5 x 12 = 60, which is greater than 58, and therefore Kangaroo’s statement is correct. Division might be used to work out the number of jumps needed by the other animals.
58 divided by 2 = 29. Hoppy takes 30 jumps because one more is needed to get across.
58 divided by 3 = 19 remainder 1, so Larry will need 20 jumps to get right across to the other side.
The problem can be simplified by reducing the number of animals and the number of stepping stones. The problem for 88 stepping stones is difficult, but it can be solved using similar reasoning.

Answers to Activity

1. Yes.
2. 5 x 12 = 60. The twelfth jump, from stone 55, would take Kangaroo to land.
3. Hoppy the Frog: 30 Larry Longlegs: 20 Flit the Flea: 15
4. Hoppy the Frog: 45 Kangaroo: 18 Larry Longlegs: 30 Flit the Flea: 23