# WitCH 125: Gordian Cutting

Here is a second one from the 2019 Year 9 NAPLAN test, this time from the calculator part.

## 5 Replies to “WitCH 125: Gordian Cutting”

1. Red Five says:

Why would Lucy do this when works equally well?

I could argue it is more logical, too.

2. Dr Mike says:

As Red Five pointed out 5 x5 + 5 x8 works the best ðŸ™‚

3. Joe says:

The area of the parallelogram is the sum of the area of the rectangle and the area of the square.

8 cm x 5 cm is the area of the rectangle, so she could use that calculation in finding the total area of the parallelogram.

4. Alasdair says:

Since 65 can only be decomposed (so to speak) into a product of numbers greater than 1 in only one way (up to commutativity): 65 = 13 Ã— 5, there can only be one possible answer. So it’s hard to know what’s being tested here, since it’s impossible to include “wrong” choices with the correct area. However, since schoolchildren now are ignorant of both times tables and of how to use a calculator correctly, maybe this is an exercise in simple arithmetic? It doesn’t help that the diagrams are not drawn to scale, even with the disclaimer. The whole thing smacks of intellectual laziness.

5. Back in Black says:

Given the triviality of the area calculation (at any level, let alone Yr 9), as pointed out by RF, the question boils down to

Which of the following is equal to 65?

(And a calculator can be used if anyone’s head hurts from doing the mental arithmetic).