Thinking Skills: Critical Thinking and Problem Solving

3.12 Making choices and decisions 123

3.12 Making choices and decisions

decisions

3.12

A is 2 × $1.29 = $2.58 for 300 g

B gives 400 g for $2.89, so 300 g is 0.75 ×

$2.89 = $2.17

C gives 600 g for 1.5 × $3.36 = $5.04 or

300 g for $2.52

D first 150 g is $1.57, second is $1.07, so

300 g is $2.64

E $1.57 for 200 g or $2.35 for 300 g

So B is the best value.

This is quite straightforward; no skills that

have not already been introduced are

involved. It is just necessary to work efficiently

and correctly, finding the most effective way

of approaching the problem.

The activity below involves making a decision.

Eve buys chickpeas in bulk to sell in her shop.

They come by volume and each drum can

contain between 10 and 12 kg. She

repackages them to sell in 0.5 kg packs. She

gets a delivery on a Monday morning and sells

anything from 8 to 15 packs in a day. She is

open 7 days a week and on Sunday night has

14 packs left and half a drum of bulk

chickpeas.

How many drums should she order to make

certain that she has enough for the next

week?

A 2 B 3 C 4 D 5 E 6

Activity

Commentary

This is a maximum and minimum type

problem: we have to combine the most

Many of the problems we encounter in
everyday life involve making choices and
decisions. To buy or not to buy? Which one
to buy? How much to buy? Which train to
take? All these are types of choice and
decision that contribute to problem-solving
processes and involve the use of skills that
can be tested by problem-solving questions.
These questions may involve skills that have
been covered in earlier chapters: extracting
information, processing data and finding
methods of solution. The only real difference is
that the question asks for a decision to be made.
The following is an example of such a question.

My local shops all have different discounts

on jars of coffee. Which of the following

represents the best value for money?

A Everlo: $1.29 for a 150 g jar

B Foodland: $2.89 for 200 g, buy one

get one free

C Springway: $3.36 for 300 g, buy one

get the second half price

D Superval: $1.57 for 150 g, 50¢

voucher off the next 150 g (one

voucher per customer)

E Massive: $1.57 for a 150 g jar with

50 g extra coffee free

Activity

Commentary
In this case it is easiest to express all the
prices to a 300 g equivalent – you may see
that this requires fewer calculations than, for
example, converting them all to 100 g.