Putting Pens to Papeer

Activity One

This activity develops students’ logic and reasoning. It will involve students looking at
combinations of equations in order to select the one that is correct. Again, the use of a table may help. The first example of the goat enclosure could be developed as follows.
If pen A has:

and A + B = 8, therefore pen B must have:

and A + C = 9, therefore pen C must have:

For B + C to equal 11, B has to have five and C has to have six, which is when A has three. Similar tables can be developed for the other questions.
It is possible to solve these problems by using quite complex equations, but students will not yet be using the level of algebra required to do such equations.

Answers to Activities

Activity One
1. 3 goats in pen A, 5 in pen B, and 6 in pen C

2. a. 2 otters in pen A, 7 in pen B, and 3 in pen C

b. 2 monkeys in pen A, 9 in pen B, 7 in pen C, and 3 in pen D

c. 10 meerkats in pen A, 3 in pen B, 5 in pen C, and 2 in pen D

d. 6 birds in pen A, 1 in pen B, 3 in pen C, and 7 in pen D

Activity Two
Answers will vary.