Measure the width and height (to the nearest cm) of the blackboard in your classroom. What is the ratio of width to height of the blackboard?

Question

Homi · Accepted Answer

Understand the Question

This is a practical activity where you measure the dimensions of a blackboard in centimeters.
The ratio of width to height is given by comparing the two measurements: $\text{Ratio} = \text{Width} : \text{Height}$ .
The ratio is simplified by dividing both quantities by their highest common factor (HCF). (Measurements may vary depending on the actual blackboard; here, standard sample values are used.)

Step 1 · Measure Blackboard Dimensions

For a standard classroom blackboard, let the measured dimensions be: Diagram 1

$\text{Width of blackboard} = 240 \text{ cm}$

$\text{Height of blackboard} = 120 \text{ cm}$

Step 2 · Calculate the Ratio

Let $W$ be the width and $H$ be the height.

\begin{aligned} \text{Ratio} &= W : H \\[0.6em] &= 240 : 120 \end{aligned}

Divide both terms by their greatest common factor ( $120$ ):

\begin{aligned} 240 \div 120 &= 2 \\[0.6em] 120 \div 120 &= 1 \end{aligned}

$\text{Ratio} = 2 : 1$

Answer

$2 : 1$

Common Mistakes

Order of Terms: Writing $\text{Height} : \text{Width}$ instead of $\text{Width} : \text{Height}$ , which would give $1 : 2$ instead of $2 : 1$ .
Mismatched Units: Measuring width in meters and height in centimeters without converting them to the same unit before forming the ratio.

Question 6