How we got there
Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.
Explain in another language · 11
1. What is the question asking?
Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Calculate 15% of R200.
Before any working — hunt first
Given
Numbers and units already in the sentence: 15% · R200. Copy each one into a column. A name without a number is not given.
Missing
After you copy the given, the letter that still has no number is missing. The paper is pointing at: 15% of R200. Circle that word — that is the missing variable.
Find
We are required to find: 15% of R200. Write that as a symbol on the left, with a question mark, before you touch a formula.
Calculate
Write 15100 with empty letters. Cross out every letter that already has a number. Calculate the letter that is still standing — that gives 15% of R200.
In other words — as if you have never seen this before
If you have never seen this before: Find 10% and 1% first when that makes the arithmetic visible, or multiply by the percentage over 100. We will name a method in words, write the formula with no numbers, then substitute one line at a time.
2. What do we already know?
15% and R200.
3. Which method — and why this one?
Find 10% and 1% first when that makes the arithmetic visible, or multiply by the percentage over 100.
4. Step-by-step working
01 / 05
Write the formula
15%=15100.
15100Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.
02 / 05
Multiply
(15/100)×200=30.
30Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.
03 / 05
Sense-check
100% of R200 is R200. 15% must be smaller than that.
R30Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.
04 / 05
Step F — Box the answer with its unit
R30
Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.
05 / 05
Step H — What the marker is looking for
On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.
Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.
5. The answer
R30
Copy onto your answer sheet — in this order
Formula: 15100
Answer: R30
6. Check it like a marker
Moving the decimal the wrong way turns 15% into 150% or into 1.5%.
7. A trap first-timers fall into
First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”