Recording measurements using a scale on an instrument, converting between metric units of length, mass and capacity, working with time and the 12 and 24 hour clock, and interpreting measurements and results to justify a decision.

What this dot point is asking

The SQA wants you to read a measurement from a scale on an instrument to a sensible degree of accuracy, convert between metric units of length, mass and capacity, work confidently with time including the 12 and 24 hour clock, and interpret measurements to justify a decision in context.

Reading a scale on an instrument

Rulers, thermometers, measuring jugs and weighing scales all use a scale with marked divisions. The skill is to find the value of each small division first, because they are rarely worth one unit each.

A sensible degree of accuracy means reading to the nearest marked division, and estimating to half a division if the pointer falls between marks.

Converting between units

Metric conversions move by multiplying or dividing by $10$, $100$ or $1000$. Going to a smaller unit multiplies (more of them); going to a larger unit divides (fewer of them).

Working with time

Time is measured in base $60$, not base $10$, so it must be handled carefully. The 24 hour clock writes times from $00\!:\!00$ to $23\!:\!59$; afternoon times add $12$ to the hour, so $3\,$pm is $15\!:\!00$.

To find a time difference, count up in stages to the next whole hour rather than subtracting the digits, because an hour is $60$ minutes.

Interpreting measurements to decide

The final numeracy skill is interpreting a result and justifying a decision. Convert everything to the same unit, compare against what the context requires, and state the decision with a reason, not just a number.

Examples in context

These skills carry into the rest of the course. A measuring scale is read before any calculation in a practical problem, units must match before quantities are added or compared, and timetable questions in the finance and measurement areas all rely on confident time arithmetic. Interpreting a measurement to make and justify a decision is exactly the applied reasoning the SQA rewards.

Try this

Q1. Convert $3.6$ kilograms to grams. [1 mark]

• Cue. $3.6 \times 1000 = 3600$ grams.

Q2. A bus leaves at $09\!:\!50$ and the journey takes $1$ hour $25$ minutes. State the arrival time. [2 marks]

• Cue. $09\!:\!50 + 1$ h $25$ min $= 11\!:\!15$.

Q3. A pointer sits two divisions above $20$ on a scale where each division is $0.5$. State the reading. [2 marks]

• Cue. $20 + 2 \times 0.5 = 21$.