Measuring correctly

Would Deepa's friends all get the same answer for the table with a metre scale? Only if they use the scale the correct way. Take care of three things.

1. Lay the scale along the object. It should touch the edge you are measuring, along its length: not lifted up, and not at a slant.

2. Keep your eye exactly above the mark. Your book shows three eye positions, A, B and C, for reading the tip of a pencil. A and C look from a slant; B looks straight down from above. B is correct. Reading from the side gives a wrong answer.

3. A broken scale still works. If the end is broken or the zero mark is unclear, start from any other full mark, say 1.0 cm. Read the mark at the other end, then subtract the starting mark.

• In the book: one end at 1.0 cm, the other at 10.4 cm. Length = 10.4 − 1.0 = 9.4 cm.
• Another: one end at 2 cm, the other at 5.5 cm. Length = 5.5 − 2 = 3.5 cm.