[S1_20150408DST] Funky Bus between Towns

Question

Introduction

     This is quite a convoluted word problem for a Secondary 1 (roughly equivalent of grade 7) pupil in Singapore.  There are a lot of data given and lots of unknowns.  How shall we cope with this?  One good way I recommend is to use a table to organise the information.  [H02]   Many primary school teachers teach the Triangle Mnemonic for the relationship between Distance, Speed and Time.  This continues to be useful in secondary school.

To get Distance, cover “Distance” with your finger, and you get Speed ´ Time.

To get Speed, cover “Speed” with your finger, and you get Distance ¸ Time.

To get Time, cover “Time” with your finger, and you get Distance ¸ Speed.

Solution

Remember: Tables are very useful to help to organise information before you try to solve the problem.  They also help you to formulate the algebraic equations correctly and quickly.

Heuristics Used

H02. Use a diagram / model

H10. Simplify the problem

H11. Solve part of the problem

H13* Use Equation / write a Mathematical Sentence

Suitable Levels
* Secondary 1 Mathematics
* precocious primary school pupils
* anyone, young or old, who enjoys an algebra challenge