Estimation, Units, and Scales

Ages 16–18

Difficulty adapts to you

Estimation, Units, and Scales

Before calculating exactly, estimate the size of the answer. Convert units consistently, state the scale of drawings or plans, and use significant figures that match the precision of the input.

Your goals

✓You can estimate quantities quickly and choose units and scales that make sense in real work.
✓You can use Estimation, Units, and Scales, model correctly.
✓You can use the definitions, units, assumptions, and examples to check your answer.

Words to know

Estimation, Units, and Scales:: Estimate quantities quickly and choose units and scales that make sense in real work.
model:: A rule or representation used to describe a situation and make a prediction.

Examples

1A room 5 m by 4 m has area about 20 m², so a result of 2,000 m² needs checking.
2On a 1:100 plan, 3 cm represents 300 cm, or 3 m.

Check these

• Do not skip the meaning of a term or give a result without explaining what it means.
• Keep every number, symbol, label, and unit in its correct place.
• Show enough working to check how you reached your answer.

Helpful habits

• Read the whole question before choosing what to do.
• Show one clear step at a time and check each step.
• If you are stuck, draw a model, try smaller numbers, or revisit the example.

Now try your own

Create your own estimation, units, and scales example, solve it, and explain how you checked it.

Professor Wise Owl

Wisdom & Understanding

“Every expert was once a beginner. You are on your way!”