Ridiculous Math Questions

Mona Reservoir, Kingston, Jamaica

I thought Math was supposed to teach children to think logically and to use their common sense in assessing whether answers were possible or not. However, when checking math homework, I came across these questions in the Grade 5 “New Integrated Approach Mathematics Workbook” by Powell, Scott and Taylor, published by PST Central Publishers (Jamaica), on page 162:

# 1. The distance around a circular swimming pool is 4.42 km. How far is the outer wall from the centre of the pool?

The answer works out to be 704 metres.  The distance across the pool would be 1408 metres – approximately 5 times the distance between the groynes at Doctor’s Cave Beach. Suppose the pool is 1 m deep,  (a safe depth since anyone getting into difficulties would otherwise drown before a life-guard could reach them), the volume of water in the pool would be 3.14 x 704 x 704 = 1,556,234 cubic metres  = approx. 1,556 million litres  or 411 million US gallons. At NWC rates, this pool would cost Ja $554,641,797.60 to fill. This is a reservoir, not a swimming pool! This distance around the Mona Reservoir is only 2.74 km!

What is the point of this ridiculous question? For children to demonstrate that they can do complicated long division sums, calculate the radius of a circle when given the circumference, and remember to (and how to) convert kilometres to metres? 

Lucea Courthouse with German clock in the tower.

#5. A circular clock in the town square is 125 m in diameter. How far is the outer edge of the clock from its centre?

My questions: What would be the weight of this clock and the mechanism used to make it work? How big is the town square? Is the clock upright or flat on the ground? If it was upright it would be about a third the height of the Empire State Building and at its widest point would fill about half a city block. How far away from it would you have to be to be able to read it? If it was flat on the ground, it couldn’t fit into a space the size of the National Stadium in Kingston, Jamaica. What would be the use of such a clock, anyway? By way of comparison, the dials on Big Ben, one of the biggest clocks in the world, are 7 metres in diameter.

The purpose of this ridiculous question is for children to demonstrate that they know that the radius of a circle is half the diameter and that they can divide 125 by 2. Surely there must be a more sensible way for children to do so. Why not asks a question about the clock in Lucea town square? This book claims to have an integrated approach, why not include some interesting history too? The clock, in the shape of a helmet worn by the German Royal Guard, was intended to be a gift from the people of Germany to the people of St. Lucia. By mistake it was sent to Lucea, Jamaica which had ordered a smaller clock from the same company. The people loved  the clock and raised the extra money to pay for it. The clock was installed in the tower in 1817.

Writers of math text books and teachers, please write sensible problems with realistic measurements that children can relate to, and that can show how math is used in everyday life. These ridiculous questions must surely alienate students who already have a negative attitude towards math.