Notes & theory for this topic

Units

Write your working on paper. Reveal each answer only after you've had a go.

1. Calculate the following conversions, giving your answers to 3 significant figures. Remember to add the units.
  1. How many kg are there in 9 lb?
    Show answer
    1 lb = 0.4536 kg
    9 lb = 4.08 kg
  2. How many l are there in 3 pt?
    Show answer
    1 pt = 0.5683 l
    3 pt = 1.70 l
  3. How many mm are there in 6 in?
    Show answer
    1 in = 25.4 mm
    6 in = 152 mm
  4. How many km are there in 5 mile?
    Show answer
    1 mile = 1.6093 km
    5 mile = 8.05 km
2. Calculate the following conversions, giving your answers to 3 significant figures. Remember to add the units.
  1. How many lb are there in 8 kg?
    Show answer
    1 kg = 2.2046 lb
    8 kg = 17.6 lb
  2. How many ft are there in 90 mm?
    Show answer
    1 mm = 0.00328 ft
    90 mm = 0.295 ft
  3. How many gal are there in 70 l?
    Show answer
    1 l = 0.22 gal
    70 l = 15.4 gal
  4. How many mile are there in 16 km?
    Show answer
    1 km = 0.6214 mile
    16 km = 9.94 mile
3. Calculate the following, giving your answers to 3 significant figures. Remember to add the units.
  1. What is the mass (kg) of 8 litres of water?
    Show answer
    1 litre of water has a mass of 1 kg
    8.00 kg
  2. What is the mass (g) of 7 centilitres of water?
    Show answer
    1 centilitre of water has a mass of 10 g
    70.0 g
  3. How many square millimetres (mm2) are there in a square of side 120 mm?
    Show answer
    area = 120 mm × 120 mm
    14400 mm2
  4. How many litres (l) are there in 8 cubic metres (m3)?
    Show answer
    1 m3 = 1000 l
    8000 l
4. Calculate the following speed conversions, giving your answers to 3 significant figures. Remember to add the units.
  1. How many m/s are there in 4000 km/hr?
    Show answer
    1 km/hr = 0.2778 m/s
    4000 km/hr = 1110 m/s
  2. How many m/s are there in 50 mph?
    Show answer
    1 mph = 0.447 m/s
    50 mph = 22.4 m/s
  3. How many m/s are there in 75 in/s?
    Show answer
    1 in/s = 0.0254 m/s
    75 in/s = 1.90 m/s
  4. How many m/s are there in 3000 ft/s?
    Show answer
    1 ft/s = 0.3048 m/s
    3000 ft/s = 914 m/s
5. Write the following numbers to the specified number of significant figures.
  1. Write 0.000136 to 2 significant figures.
    Show answer
    0.00014
  2. Write 1681.58 to 3 significant figures.
    Show answer
    1680
  3. Write 740870 to 4 significant figures.
    Show answer
    740900
  4. Write 0.01554 to 3 significant figures.
    Show answer
    0.0155
6. Give the following numbers in scientific notation. Write 1.23 × 104 as 1.23E4. Do not change the number of significant figures.
  1. Write 0.00499 in scientific notation.
    Show answer
    4.99E-3
  2. Write 0.0000187 in scientific notation.
    Show answer
    1.87E-5
  3. Write 0.03816 in scientific notation.
    Show answer
    3.816E-2
  4. Write 272.92 in scientific notation.
    Show answer
    2.7292E2
7. Give the following numbers in engineering notation (the exponent is a multiple of 3). Write 1.23 × 104 as 1.23E4. Do not change the number of significant figures.
  1. Write 1064.4 in engineering notation.
    Show answer
    1.0644E3
  2. Write 0.000626 in engineering notation.
    Show answer
    626E-6
  3. Write 1576410 in engineering notation.
    Show answer
    1.576410E6
  4. Write 0.01344 in engineering notation.
    Show answer
    13.44E-3
New questions