Copyright © University of Cambridge. All rights reserved.
Have a look at the sets of four quantities below. Can you rank them in order from smallest to largest?
To help you to decide on your rankings, you may need to find extra information or carry out some experiments.
Can you provide convincing evidence of your final rankings?
Time For light to reach us from the nearest star other than the sun That a pet rat lives Between two football world cups For all of the red blood cells in your body to be replaced....10 times 

Distance You can hop in 5 seconds A car can drive on $1$cm$^3$ of fuel From the top of a 6 storey building to the ground The distance from the penalty spot to the goal on a football field 

Speed Of a racehorse running at maximum speed Of the fastest sprinter in the world Of the fastest cyclist in an Olympic cycle sprint race Of a bus going past the school 

Mass Of a standard family car Of a million cubic centimetres of water Of a team of international male rugby players (15 players) Of enough potatoes to make chips to feed everyone in the school for a week. 

Volume of water In a halffilled bath Used in a 10 minute shower Used in 5 dishwasher cycles Used to flush the toilet 20 times 

Number of Mars bars with the same total weight as your whole class Steps when walking at a leisurely pace for 1 hour Stitches in a handknitted jumper People at a cup final in a large stadium 

Area Of the sheets of paper in a ream (500 sheets) of A4. Of the floor of the classroom Covered by 5 litres of paint Of fabric needed to make school uniforms for the whole class. 
Perhaps you might like to make 4 ranked quantities of your own to challenge a friend.
For more advanced science, see Approximately Certain.