Question

How many cm are there in a decimetre?

• A. 40 cm
• B. 10 cm
• C. 20 cm
• D. 30 cm

Hint:

Think of the metric ladder: metre → decimetre → centimetre → millimetre. Each step down is a multiplication by 10. So, 1 metre is 10 decimetres, and 1 decimetre is 10 centimetres.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept
The question asks for the conversion between centimetres and decimetres.
Step 2: Detailed Explanation
Let's use the metre as our base unit.
1 metre = 10 decimetres (dm)
1 metre = 100 centimetres (cm)
From this, we can establish a relationship:
\[ 10 \text{ dm} = 100 \text{ cm} \] To find the value of 1 decimetre, we divide both sides by 10:
\[ \frac{10 \text{ dm}}{10} = \frac{100 \text{ cm}}{10} \] \[ 1 \text{ decimetre} = 10 \text{ centimetres} \]