Year 7 Science — Measuring length

Say why standard units are needed, convert between kilometre, metre, centimetre and millimetre, and read a scale the right way.

Name: ________________________

Before you start

Slide along this 15-centimetre scale. Between each pair of big marks there is 1 cm, and each of those is cut into 10 parts of 1 mm.

The smallest length this scale can measure is 1 mm, which is one-tenth of one of these steps.

1.A length is written down as "25 cm". The chapter says a length is written in two parts. What are they?
- a) A measurement and an estimate
- b) A number and a symbol
- c) A reading and a reference point
- d) A number and a unit
2.A 15-cm scale is drawn out below. Which mark sits at 7 cm?
Mark the line with an X.
3.You want to measure the girth of a tree trunk. Which is the right instrument?
- a) A flexible measuring tape
- b) A pair of dividers
- c) A rigid metre scale
- d) A 15-cm plastic scale
4.Which of these is written correctly, following the chapter's rule for unit symbols?
- a) 15 cms
- b) 15 cm.
- c) 15 cm
- d) 15 Cm
5.A road is 7 km long. How many metres is that? Answer with a number.
6.Sort each unit by whether it is a standard unit or one taken from the body.
Groups: Standard unit · Unit taken from the body
- Handspan
- Metre
- Angula
- Kilometre
- Centimetre
7.A stick is laid against a broken scale. One end reads 3.0 cm and the other reads 14.0 cm. How long is the stick, in centimetres?
- a) 17.0
- b) 11.0
- c) 14.0
- d) 3.0
8.Where should your eye be when you read a length off a scale?
- a) Well off to the right of the point
- b) As far back from the scale as you can get
- c) Directly above the point being read
- d) Well off to the left of the point

1. d) A number and a unit
2. 7
3. a) A flexible measuring tape
4. c) 15 cm
5. 7000
6. Centimetre → Standard unit; Kilometre → Standard unit; Metre → Standard unit; Handspan → Unit taken from the body; Angula → Unit taken from the body
7. b) 11.0
8. c) Directly above the point being read