How To Remember Formulas Easily In Singapore: A Practical Tutorial For O Level Math & Science

If you’re taking your O Levels or streaming exams in Singapore, you already know this: math and science are not just about understanding concepts — they’re also about remembering a mountain of formulas.

Quadratic formula, kinematics equations, lens formula, trigonometry identities, chemical equations, physics definitions… it can feel endless, especially when you’re juggling CCA, homework, and other subjects.

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In this guide, I’ll walk you through:

• A step-by-step tutorial on how to remember formulas easily (and actually keep them in your head till exams)
• Exam strategy tips specific to O Level / Sec 3–4 math and science
• Worksheet-style practice ideas with easy, medium, and hard variants you can try right away
• Common mistakes students in Singapore make when trying to memorise formulas

Along the way, I’ll also show you how to use Tutorly.sg — a 24/7 AI tutor website built specifically for Singapore’s MOE syllabus — to drill formulas, test yourself, and fix weak areas quickly.

Tutorly.sg has already been used by thousands of students in Singapore and has even been mentioned on Channel NewsAsia (CNA), so you’re in good company if you use it as part of your study routine.

You can open Tutorly here (keep it in a tab as you read this):

• Main AI Tutor: <https://tutorly.sg/ai-tutor-singapore>
• Direct access to the web app: <https://tutorly.sg/app>

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Step-by-step tutorial: A system to remember formulas (and not forget them 2 days later)

Instead of trying to “just memorise”, use a repeatable system. Here’s a 6-step method you can apply to almost any O Level math or science formula.

Step 1: Group formulas by topic, not by chapter list

Your textbook may jump around, but your brain remembers connections, not random lists.

For example, in Additional Math (A Math), instead of:

• Quadratic formula
• Discriminant
• Completing the square
• Graphs of quadratic functions

Group them as:

“Everything about quadratic equations and graphs”

So your “quadratic bundle” might include:

• Standard form: $ax^2 + bx + c = 0$
• Quadratic formula:
  $x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2 a}$
• Discriminant: $D = b^2 - 4ac$
• Vertex form: $y = a(x - h)^2 + k$

Do the same for Physics:

“Everything about kinematics”

• $v = u + at$
• $s = ut + \frac{1}{2}at^2$
• $v^2 = u^2 + 2as$

Why this works: during exams, questions are set by topic, not by “Page 72 formula 3.1”. Grouping by topic helps your brain retrieve the whole cluster faster.

Action you can take today:
Make a one-page “Formula Map” for each major topic (e.g. Trigonometry, Kinematics, Electricity). Don’t write full notes — just formulas. Stick it near your study table.

You can then use Tutorly.sg to ask:

“I’m Sec 4 O Level Physics. Give me a topic-wise formula list for Kinematics and then test me with 10 questions that require choosing the correct formula.”

Tutorly will generate questions, and you can see which formulas you keep mixing up.

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Step 2: Understand the formula before you memorise it

You’ve probably heard teachers say, “Don’t just memorise, understand.” But what does that actually mean for a formula?

Let’s take the Ohm’s Law formula in Physics:

$V = IR$

To “understand” it, ask yourself:

• What does each symbol stand for?

  • $V$ = voltage (potential difference), measured in volts (V)
  • $I$ = current, measured in amperes (A)
  • $R$ = resistance, measured in ohms ($\Omega$)

• How do they relate in real life?
  If resistance $R$ is fixed and you increase $V$, current $I$ increases.

• How can I rearrange it?

  • $I = \frac{V}{R}$
  • $R = \frac{V}{I}$

Same for the area of a circle in E Math:

$A = \pi r^2$

Don’t just chant it. Visualise: if you double the radius $r$, the area becomes four times bigger (since $2^2 = 4$). This gives the formula meaning, which makes it stick better.

How to use Tutorly for this step:
Type something like:

“Explain $v^2 = u^2 + 2as$ in Sec 3 Physics using simple examples, then give me 3 questions to check if I really understand.”

You’ll get both explanation and practice in one place.

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Step 3: Use short, personal mnemonics (not long lame ones)

Mnemonics are powerful, but if the sentence is too long or weird, you’ll forget it anyway.

For example, SOH CAH TOA for trigonometry:

• $\sin \theta = \dfrac{\text{Opposite}}{\text{Hypotenuse}}$
• $\cos \theta = \dfrac{\text{Adjacent}}{\text{Hypotenuse}}$
• $\tan \theta = \dfrac{\text{Opposite}}{\text{Adjacent}}$

Instead of some random sentence, remember the pattern:

• S O H → Sine = Opposite / Hypotenuse
• C A H → Cosine = Adjacent / Hypotenuse
• T O A → Tangent = Opposite / Adjacent

For Physics kinematics:

You can group them by what they give you:

• No $s$: $v = u + at$
• No $v$: $s = ut + \frac{1}{2}at^2$
• No $u$: $s = vt - \frac{1}{2}at^2$
• No $t$: $v^2 = u^2 + 2as$

Turn this into a mini-checklist in your head:
“Which variable is missing? Use that equation.”

Action:
Pick 3 formulas you always forget and create:

1. A short phrase or pattern
2. A 1-line explanation in your own words

You can even ask Tutorly:

“Help me create simple mnemonics to remember the formulas for sine rule and cosine rule for O Level A Math.”

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Step 4: Use the “Look–Cover–Write–Check” method (but for formulas)

This is a classic method used for spelling, but it works very well for formulas too.

1. Look at the formula.
   Example: $F = ma$

2. Cover it with your hand / paper.

3. Write it from memory on another page.

4. Check:

   • Did you get the letters correct?
   • Did you miss any squares, roots, or fractions?

5. Repeat until you can write it correctly three times in a row without looking.

Do this for a small set of formulas $e.g. 5–8 at a time$. Don’t try to cram 30 formulas at once.

How Tutorly can help:
Ask:

“Give me a blank formula test for O Level E Math trigonometry, where you show the situation and I have to recall the formula.”

You can then type the formula you think is correct, and see if Tutorly’s worked solution matches your version.

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Step 5: Apply the formula immediately to simple questions

Your brain remembers formulas better when you use them straight away.

Example: For the quadratic formula, instead of just memorising:

$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2 a}$

Do a quick mini-drill:

1. $x^2 - 5 x + 6 = 0$
2. $2 x^2 + 3 x - 2 = 0$
3. $3 x^2 - 4 x + 1 = 0$

Each time, identify $a, b, c$, substitute, and solve.

Same for Physics:

After memorising $v = u + at$, try:

1. A car starts from rest and accelerates at $2.0 \, \text{m/s}^2$ for 5 s. Find its final velocity.
2. A ball is thrown upwards at $10 \, \text{m/s}$ with $a = -9.8 \, \text{m/s}^2$. Find its velocity after 2 s.

Use Tutorly here:
Go to <https://tutorly.sg/ai-tutor-singapore> and type:

“I just revised the kinematics formulas. Give me 10 basic practice questions that each focus on only one formula at a time, and show full solutions after I answer.”

This gets the formula into your “muscle memory”.

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Step 6: Schedule spaced repetition (don’t cram the night before)

Your brain forgets quickly if you don’t review. A simple schedule:

• Day 1: Learn + practise (small set of formulas)
• Day 2: Quick review $5–10 minutes$
• Day 4: Review again (testing yourself)
• Day 7: Short test (no notes)
• Day 14: Final check

You can use Tutorly as your on-demand quiz maker:

“I want to review O Level Chemistry formulas for concentration and moles. Give me 5 quick questions now, and then 5 harder ones.”

Because Tutorly is available 24/7 at <https://tutorly.sg/app>, you can squeeze in these mini-reviews even on busy days — between tuition, CCA, or on the bus.

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Exam strategy guide: Using formulas smartly in O Level papers

Memorising formulas is only half the battle. You also need to know when and how to use them under exam pressure.

“Access more than 1000+ past year papers to practice”
👉 Start a paper today and test yourself like it’s the real exam.

Here’s how to handle formulas in exams for E Math, A Math, Physics, and Chemistry.

1. Read the question and identify the topic first, not the formula

Common mistake: students scan for numbers and randomly pick a formula that “looks right”.

Better approach:

1. Ask: “Which topic is this?”

   • Trigonometry?
   • Kinematics?
   • Forces?
   • Stoichiometry?

2. Then ask: “Within this topic, what kind of situation is this?”

   • Right-angled triangle?
   • Projectile motion?
   • Series / parallel circuit?
   • Limiting reagent?

3. Only then choose the formula.

Example (Physics):

“A car of mass $800 \, \text{kg}$ accelerates from rest to $20 \, \text{m/s}$ in 5 s. Find the resultant force.”

• Topic: Dynamics
• Situation: Force causing acceleration
• Steps:
  1. First use $a = \dfrac{v - u}{t}$
  2. Then use $F = ma$

If you jump straight to $F = ma$ without finding $a$, you’ll get stuck.

You can practise this “topic identification” using Tutorly by asking:

“Give me mixed O Level Physics questions where I must first state the topic and formula before solving. Then show me the correct topic and formula in your solution.”

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2. Write the formula clearly before substituting numbers

Examiners in O Level marking schemes award marks for:

1. Correct formula
2. Correct substitution
3. Correct final answer (with units)

So even if you somehow mess up the arithmetic, you can still earn method marks.

Example (E Math):

Find the area of a sector of radius 7 cm and angle $60^\circ$.

Write:

1. Formula:
   $\text{Area of sector} = \frac{\theta}{360^\circ} \times \pi r^2$
2. Substitution:
   $= \frac{60^\circ}{360^\circ} \times \pi \times 7^2$
3. Simplify:
   $= \frac{1}{6} \times \pi \times 49$
   $\approx 25.7 \, \text{cm}^2$

Even if you mis-key the calculator slightly, you may still get 1–2 marks.

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3. Rearrange formulas carefully (especially in Physics & Chemistry)

Many O Level questions test whether you can rearrange formulas, not just plug in numbers.

Example (Physics – Density):

$\rho = \frac{m}{V}$

You might need:

• $m = \rho V$
• $V = \frac{m}{\rho}$

Example (Chemistry – Concentration):

$\text{Concentration} = \frac{\text{Number of moles}}{\text{Volume in dm}^3}$

So:

• $\text{Number of moles} = \text{Concentration} \times \text{Volume}$

Exam tip: When rearranging:

1. Write the original formula.
2. Do one algebra step at a time (don’t jump).
3. Circle the final subject of the formula.

You can get timed practice by asking Tutorly:

“Give me 10 O Level Physics questions where I have to rearrange formulas (e.g. density, speed, pressure, Ohm’s law) and then solve.”

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4. Use estimation to check if your answer is reasonable

Even if you remember the formula, you can still make careless mistakes. Quick estimation helps catch them.

Examples:

• If a car accelerates at $2 \, \text{m/s}^2$ for 5 s, you expect the change in speed to be around $10 \, \text{m/s}$. If your answer is $100 \, \text{m/s}$, something’s off.
• If the radius of a circle is 10 cm, the area should be around $300 \, \text{cm}^2$ (since $\pi \approx 3$ and $10^2 = 100$). If you get $30 \, \text{cm}^2$, that’s suspicious.

Train this with Tutorly by adding:

“After each question, explain if my answer is reasonable using estimation.”

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5. Prioritise formula-heavy questions in your revision

Look at the O Level syllabus and past-year papers. Certain topics are formula-dense and appear almost every year:

• E Math: Trigonometry, Coordinate Geometry, Mensuration, Probability
• A Math: Quadratics, Trigonometry identities, Differentiation, Integration
• Physics: Kinematics, Dynamics, Work/Energy/Power, Electricity
• Chemistry: Moles, Concentration, Gas laws (if in your syllabus), Energy changes

Spend more of your formula-memorising energy on these topics, because they give you high returns in marks.

You can ask Tutorly:

“Show me a topic-by-topic breakdown of formula-heavy areas for O Level E Math and test me on each topic.”

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Worksheet practice: From easy to hard (with tough variants)

Let’s turn all this into actual practice. Below are sample worksheet-style questions you can try. After each section, I’ll suggest how to extend it using Tutorly.

A. E Math – Trigonometry & Mensuration

Level 1 – Basic recall

1. State the formula for:

   • (a) Area of a circle
   • (b) Circumference of a circle
   • (c) Area of a triangle (using base and height)
   • (d) Pythagoras’ theorem

2. Write down the SOH CAH TOA relationships.

3. State the formula for the length of an arc of a circle of radius $r$ and angle $\theta$ in degrees.

Check yourself before looking at notes.

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Level 2 – Application

4. A circle has radius 6 cm. Find:

   • (a) its area
   • (b) its circumference

5. A right-angled triangle has hypotenuse 13 cm and one side 5 cm. Find the length of the other side.

6. A sector of a circle has radius 10 cm and angle $72^\circ$. Find:

   • (a) the length of the arc
   • (b) the area of the sector

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Level 3 – Harder variants (exam-style)

7. A circular field has radius 20 m. A path of uniform width $x$ m is built around the field. The total area of the field and path is $1760\pi \, \text{m}^2$.

   • (a) Write an expression for the total area in terms of $x$.
   • (b) Form an equation and find the width of the path.

8. A ladder leans against a vertical wall, making an angle of $65^\circ$ with the horizontal ground. The foot of the ladder is 3.5 m from the wall.

   • (a) Find the length of the ladder.
   • (b) Find the vertical height reached by the ladder on the wall.
   • (c) If the ladder is 0.5 m longer, what angle will it now make with the ground, assuming the foot is at the same place?

These questions force you to choose the correct formula, not just remember it.

Using Tutorly for more practice:
Ask:

“Generate a 20-question E Math worksheet on trigonometry and mensuration, with at least 5 hard exam-style questions involving algebraic expressions and unknowns in the formulas. Show worked solutions after each answer.”

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B. Physics – Kinematics & Dynamics

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👉 Try Tutorly now and start a Science topic in seconds.

![Secondary Science topics you can practise on Tutorly.sg]$/app/blog-images/middle 2.png$

Level 1 – Basic recall

9. State the four constant-acceleration (SUVAT) equations.

10. Write the formulas for:

    • (a) Speed
    • (b) Acceleration
    • (c) Force $Newton’s 2nd law$
    • (d) Weight

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Level 2 – Application

11. A car moves at a constant speed of $18 \, \text{m/s}$ for 30 s. Find the distance travelled.

12. A ball is dropped from rest and accelerates at $9.8 \, \text{m/s}^2$. Find its speed after 4 s.

13. A resultant force of 50 N acts on a mass of 10 kg. Find its acceleration.

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Level 3 – Harder variants (exam-style)

14. A car of mass 900 kg accelerates uniformly from $12 \, \text{m/s}$ to $24 \, \text{m/s}$ in 8 s.

    • (a) Find its acceleration.
    • (b) Find the resultant force acting on the car.
    • (c) Hence find the distance travelled during this time.

15. A ball is thrown vertically upwards with an initial speed of $20 \, \text{m/s}$. Take $g = 10 \, \text{m/s}^2$.

    • (a) Find the time taken to reach the highest point.
    • (b) Find the maximum height reached.
    • (c) Find the speed of the ball when it is 15 m above the point of projection.

These require you to choose the correct kinematics equation and often use two formulas in one question.

Using Tutorly for more practice:
Ask:

“I want a mixed O Level Physics worksheet on kinematics and dynamics with 5 easy, 5 medium, and 5 challenging questions. Focus on choosing the correct formula and show full worked solutions after each question.”

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C. Chemistry – Moles & Concentration

Level 1 – Basic recall

16. State the formula for:
    • (a) Number of moles from mass
    • (b) Concentration in $\text{mol/dm}^3$
    • (c) Number of moles of gas at room temperature and pressure (if in your syllabus)

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Level 2 – Application

17. Calculate the number of moles in:

    • (a) 10 g of sodium ($\text{Na}$), given that the molar mass of Na is 23 g/mol.
    • (b) 49 g of sulfuric acid, $\text{H}_2\text{SO}_4$ $molar mass = 98 g/mol$.

18. A solution contains 0.5 mol of sodium chloride in $250 \, \text{cm}^3$ of solution. Find its concentration in $\text{mol/dm}^3$.

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Level 3 – Harder variants (exam-style)

19. 25.0 cm³ of 0.200 $\text{mol/dm}^3$ hydrochloric acid is completely neutralised by sodium hydroxide solution. Write the equation for the reaction and calculate:

    • (a) the number of moles of hydrochloric acid used
    • (b) the number of moles of sodium hydroxide used
    • (c) the concentration of the sodium hydroxide solution if 20.0 cm³ is required.

20. 5.85 g of sodium chloride is dissolved in water to make 500 cm³ of solution.

    • (a) Calculate the number of moles of sodium chloride. $Molar mass of NaCl = 58.5 g/mol$
    • (b) Calculate the concentration of the solution in $\text{mol/dm}^3$.

These questions test your ability to use formulas in multiple steps and convert between units.

Using Tutorly for more practice:
Ask:

“Generate a challenging O Level Chemistry worksheet on moles and concentration, including multi-step questions where I must use more than one formula. Then mark my final answers and show me full step-by-step solutions.”

Remember: Tutorly checks your final answer and then shows you how to get there, so you can compare your own working with a clear model solution.

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Common mistakes students make when memorising formulas

You might be studying hard but still not seeing marks improve. Often, it’s because of these common mistakes.

1. Trying to memorise everything at once

Cramming 40 formulas in one night feels productive, but you’ll forget most of them within days.

Fix:
Use small batches $5–8 formulas$ and the spaced repetition schedule from earlier. Link them by topic.

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2. Memorising symbols without understanding units

Students often remember $F = ma$ but forget:

• $F$ in newtons (N)
• $m$ in kilograms (kg)
• $a$ in $\text{m/s}^2$

Then they plug in grams or cm and get weird answers.

Fix:
When you write a formula, always write the units at least a few times during revision. For example:

$F (\text{N}) = m (\text{kg}) \times a (\text{m/s}^2)$

You can ask Tutorly:

“Give me 10 Physics questions that test both formulas and correct SI units, and explain where students often go wrong with units.”

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3. Not practising formula selection (only recall)

Many students can recite formulas perfectly, but in the exam

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Ready to practise?

If you want a Singapore-focused AI tutor you can use immediately $website, no sign-up$, try Tutorly here:

• https://tutorly.sg/ai-tutor-singapore
• https://tutorly.sg/app

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