**Problem / Question**

This problem for primary 5 from one of my
acquaintances on Facebook, considered to be of intermediate level difficulty (in
Singapore ). But it looks rather challenging to draw all
those bar diagrams, doesn’t it?

Here is my quickie solution without
explicit algebra and without bar diagrams.

**Solution**

For convenience, we use 6 circle units for
Eclairs and 6 square units for Macaroons.

Suppose there
were half as many Eclairs and Macaroons, then there would be 15 more
Eclairs. So 3 square units add 15 can be
changed to 3 circle units.

Add 15 to the 17 and change 3 square units
to 2 circle units. We deduce that 5
circle units is the same as 85. From
here we can easily figure out the rest.

**Ans:**102 éclairs.

**Comment**

The problem can be solved by bar
diagrams. However, there are many ways
to skin the cat. For more good stuff, please join my Facebook group “Effective and Elegant
Mathematics”.

H02. Use a
diagram / model

H05. Work
backwards

H06. Use
before-after concept

H08. Make suppositions

H09. Restate
the problem in another way

H11. Solve part
of the problem

**Suitable Levels**

*****Primary School / Elementary School Mathematics

* any precocious or independent learner who is
interested

## No comments:

## Post a Comment