Most Science calculations need four small maths skills, not advanced Mathematics. If you can find which of the four is letting you down, the rest of the question usually opens up.
This page sits under the SPM Science learning guide. It is for the student who says, “I know what the question is about, but I get lost when numbers appear.”
What does the problem look like in your words?
“I read the question and understand it. Then I see two numbers and a formula and I do not know where to put them.”
Another version: “My answer is a strange number, and I cannot tell if it is wrong.” Both come from a short list of causes.
Which four skills cause most of the trouble?
Test yourself on each one. If a line below feels shaky, that is where to start.
| Skill | One-line test | Where it shows up |
|---|---|---|
| Substituting into a formula | Put 45 m and 9 s into speed = distance ÷ time | Motion, density, energy |
| Rearranging a formula | Make time the subject of speed = distance ÷ time | Finding an unknown quantity |
| Converting units | Write 250 mL in litres and 1.2 km in metres | Practical data tables |
| Percentage and ratio | A plant grows from 20 cm to 26 cm: what is the percentage increase? | Growth, efficiency, mixtures |
Answers to the tests: speed = 45 ÷ 9 = 5 m/s; time = distance ÷ speed; 250 mL = 0.25 L and 1.2 km = 1 200 m; the increase is 6 ÷ 20 × 100 = 30%.
Worked example: a rate question in full sentences
A trolley travels 45 m in 9 s along a straight track. The teacher asks how long it needs to travel 60 m at the same speed.
Step 1: find the speed. Speed = distance ÷ time = 45 m ÷ 9 s = 5 m/s.
Step 2: rearrange. From speed = distance ÷ time, time = distance ÷ speed.
Step 3: substitute. Time = 60 m ÷ 5 m/s = 12 s.
Step 4: state the assumption. The answer holds only if the speed stays at 5 m/s for the whole track. If the trolley speeds up or slows down, 12 s is not reliable.
Notice the units travel with every number. When the final unit is seconds, you know the working at least hangs together.
Why do right methods give wrong answers?
The slip is seldom the Science. Three habits cost the most marks in this kind of question.
- Converting too late. You put 250 into a formula that needs litres, and the answer comes out 1 000 times too large.
- Rounding too early. Rounding 5.666 to 5.7 in step one, then multiplying, drifts the final answer.
- Rearranging by feel. You swap the numbers without writing the new formula, so the division ends up upside down.
A quick estimate catches all three. In the trolley question, 60 m is more than 45 m, so the time should be more than 9 s. An answer of 0.08 s or 108 s fails that check at once.
What can you do this week without a teacher?
Keep it small. Ten minutes a day for five days is a fair start.
- Pick one skill from the table, the one where your test line felt weakest.
- Write five practice lines for it using numbers from your own textbook.
- Write the unit next to every number, including the answer.
- After each answer, do a rough estimate in one line.
- Record any slip in the mistake log and paper-error review so you can see if the same one repeats.
If your difficulty is reading graphs rather than arithmetic, the graph evidence and fair-comparison lab gives you data to practise on. Calculations that appear inside practical questions are covered in laboratory safety and investigation.
When might one-to-one tuition be worth considering?
Consider it when the same kind of slip returns after a fortnight of practice, or when you cannot tell which of the four skills is the problem. A teacher can look at your first two lines of working and see the gap, which is hard to do alone.
Tuition does not replace your school Mathematics class. It works on the maths that Science needs, using your own questions. To see how this works for Science, read about online one-to-one Science tuition, or the one-hour trial class (from RM50), which is a real taught lesson.