Author: Erada Oguntoye
Platform: Brashan Chemistry Website
Date: Tuesday, 31 March 2026
Topic: 7 Mistakes You’re Making with A-Level Chemistry Calculations (Part 1 of 4)

Do calculations feel like the "boss level" of your A-Level Chemistry journey? You aren't alone. Chemistry math is a unique beast, blending complex theory with high-stakes arithmetic. To truly unlock your top grade, you need to master the art of the calculation.

At Brashan Chemistry, we’ve spent years helping students elevate their understanding from confusion to clarity. I’m Dr. Erada Oguntoye, and over my 30+ years of teaching, I have had the privilege of helping 15,000+ students find their "aha!" moment. I’ve seen every mistake in the book, and today, we’re going to dive into the first two major pitfalls holding you back.

1. The "Ghost" Method: Not Showing Your Working

Many students treat their exam paper like a scratchpad, jotting down a final answer and hoping for the best. This is a dangerous game! If you hit the wrong button on your calculator but have no working, you lose every single mark.

To empower your score, write down every step. Start with the formula, show the substitution, and then the result. Even if the final number is slightly off, examiners can award method marks that unleash your hidden potential.

2. The Calculator Trap: Careless Arithmetic

It’s easy to feel invincible with a scientific calculator in your hand, but simple data entry errors are grade-killers. Whether it's a misplaced decimal point or forgetting a bracket in a complex fraction, arithmetic slips can cause your achievements to plummet.

How to excel: Always perform your calculation twice. If you get the same answer twice, you’re likely safe. If not, it’s time to re-evaluate. 🚀

Dr. Erada Oguntoye guiding a student through a complex titration calculation to ensure precision and accuracy.

Join Our Community and Soar

Don't let calculation errors stop you from reaching your dream university. Our Summer Booster classes are designed to help you soar past these hurdles.

PROMO ALERT: Book your Summer Booster before the end of June and enjoy a 10% early-bird discount! Discover our holistic approach here.

Let's journey together toward that A*.

CONTACT US:
Visit: brashanchemistry.com/contact
Fill out our form: landing.brashanchemistry.com/form

TERMS AND CONDITIONS: THE 10% EARLY-BIRD DISCOUNT IS VALID ONLY FOR SUMMER BOOSTER PROGRAMME BOOKINGS COMPLETED AND PAID BEFORE 11:59 PM ON JUNE 30, 2026. DISCOUNT CANNOT BE COMBINED WITH OTHER OFFERS. BRASHAN CHEMISTRY RESERVES THE RIGHT TO MODIFY OR CANCEL PROMOTIONS AT ANY TIME. ALL TUTORING SESSIONS ARE SUBJECT TO AVAILABILITY.

Author: Erada Oguntoye
Platform: Brashan Chemistry Website
Date: Tuesday, 31 March 2026
Topic: 7 Mistakes You’re Making with A-Level Chemistry Calculations (Part 2 of 4)

7 Mistakes You’re Making with A-Level Chemistry Calculations (and How to Fix Them)

In our last post, we talked about showing your working and calculator caution. Now, let’s unleash your skills further by tackling two of the most common technical errors in A-Level Chemistry: units and rounding.

3. The Unit Conversion Catastrophe

Chemistry is full of different units. You might be given a volume in cm³ but need it in dm³ for a concentration calculation, or a temperature in Celsius that must be in Kelvin for gas laws. Forgetting to convert these is like trying to fit a square peg in a round hole: it simply won't work.

To excel, always double-check your units before you start. For example, when calculating ΔH, you often get energy in Joules (J) but need to report it in kilojoules (kJ). Dividing by 1,000 is a small step that makes a massive difference to your final grade. Elevate your accuracy by writing the units next to every number in your working.

4. Premature Rounding in Empirical Formulae

Rounding too early is a silent grade-killer. If you round your molar ratios to the nearest whole number before you’ve finished the calculation, you’ll end up with the wrong empirical formula.

If you get a ratio of 1.51, don't round it to 2! Instead, identify the fraction (1.5 is 3/2) and multiply all ratios by 2 to get whole numbers. This precision is what allows your chemistry results to soar to the highest levels.

Dr. Erada Oguntoye demonstrating how to handle molar ratios and unit conversions on a digital whiteboard.

Ready to Unleash Your Full Potential?

If these calculations are making your head spin, we are here to help you excel. Our community of students is learning to tackle these problems with confidence and ease.

Don’t forget: Book your Summer Booster by the end of June to claim your 10% early-bird discount! Learn why active learning is the key to your success here.

STAY UP TO DATE:
Check our latest blogs: brashanchemistry.com/blog
Visit our website: brashanchemistry.com

TERMS AND CONDITIONS: THE 10% EARLY-BIRD DISCOUNT IS VALID ONLY FOR SUMMER BOOSTER PROGRAMME BOOKINGS COMPLETED AND PAID BEFORE 11:59 PM ON JUNE 30, 2026. BRASHAN CHEMISTRY RESERVES THE RIGHT TO AMEND TUTORING SCHEDULES BASED ON TUTOR AVAILABILITY. ALL CURRICULUM MATERIAL IS PROPERTY OF BRASHAN CHEMISTRY.

Author: Erada Oguntoye
Platform: Brashan Chemistry Website
Date: Tuesday, 31 March 2026
Topic: 7 Mistakes You’re Making with A-Level Chemistry Calculations (Part 3 of 4)

7 Mistakes You’re Making with A-Level Chemistry Calculations (and How to Fix Them)

We’ve covered the basics and the technicalities. Now, let’s dive into the nuances that separate the B students from the A* superstars. Precision and logic are your best friends in the exam room.

5. Significant Figure Slip-ups

Significant figures (sf) are not just a suggestion; they are a requirement. Many students lose easy marks by giving an answer to 5 decimal places when the data provided was only given to 3 significant figures.

To empower your performance, always match the precision of your final answer to the least precise piece of data given in the question. This shows the examiner you understand the limits of experimental data. Watch your scores soar as you master this simple rule.

6. Using the Wrong Formula (or the Wrong Mass)

It sounds simple, but in the heat of an exam, it’s easy to grab the wrong number. A classic example is the $q = mcΔT$ calculation. Students often use the mass of the fuel burned instead of the mass of the water being heated.

To unleash your full accuracy, read the question twice. Circle the quantities you need and label them ($m$, $c$, $ΔT$) before you even touch your calculator. This methodical approach will elevate your confidence and ensure you are applying the right theory to the right numbers.

Dr. Erada Oguntoye explaining the energy changes in calorimetry and highlighting where students often trip up.

Transform Your Year 12 Experience

Are you ready to soar? Don't wait until the week before exams to fix these habits.

URGENT: Our Summer Booster slots are filling up fast! Book before the end of June to secure your 10% discount. We've helped over 15,000 students excel, and you’re next.

GET IN TOUCH:
Website: brashanchemistry.com
Direct Contact: brashanchemistry.com/contact

TERMS AND CONDITIONS: DISCOUNT APPLIES TO NEW BOOKINGS ONLY. PARTICIPANTS MUST BE ENROLLED IN AN A-LEVEL OR GCSE PROGRAMME. REFUNDS ARE SUBJECT TO THE BRASHAN CHEMISTRY CANCELLATION POLICY AS OUTLINED ON OUR MAIN WEBSITE.

Author: Erada Oguntoye
Platform: Brashan Chemistry Website
Date: Tuesday, 31 March 2026
Topic: 7 Mistakes You’re Making with A-Level Chemistry Calculations (Part 4 of 4)

7 Mistakes You’re Making with A-Level Chemistry Calculations (and How to Fix Them)

We have reached the final part of our series! We’ve looked at working out, units, rounding, and formulas. To wrap things up, we need to talk about the very foundation of your success.

7. A Weak Foundation in the Basics

The most complex A-Level enthalpy or buffer calculation still relies on one thing: the mole. If your understanding of mole calculations, stoichiometry, or basic acid-base theory is shaky, the higher-level topics will feel impossible.

To unleash your full potential, you must revisit your GCSE or early Year 12 foundations. Don’t be afraid to go back to basics. Once the foundation is solid, your ability to tackle application questions will soar. 🚀

Your Journey to Excellence Starts Here

With 30+ years of experience, I’ve seen that any student can excel if they have the right guidance and the right habits. Chemistry calculations aren't a wall; they are a ladder to your future career in science or medicine.

Don’t miss out: Our Summer Booster is the perfect place to bridge the gap between "I'm struggling" and "I've got this."

• 10% Early-bird Discount if you book before the end of June!
• Expert guidance from Dr. Erada Oguntoye.
• A community focused on student success.

Dr. Erada Oguntoye celebrating a student's progress and encouraging them to keep pushing for their goals.

BOOK NOW:
Explore our programs: brashanchemistry.com/services-a-holistic-approach
Start your journey: landing.brashanchemistry.com/form

Let’s empower your future together. See you in the booster sessions!

TERMS AND CONDITIONS: ALL PROMOTIONAL OFFERS ARE SUBJECT TO AVAILABILITY AND MAY BE WITHDRAWN WITHOUT NOTICE. THE 10% DISCOUNT APPLIES TO THE TOTAL COST OF THE SUMMER BOOSTER PROGRAMME. BRASHAN CHEMISTRY IS NOT RESPONSIBLE FOR EXAM OUTCOMES BUT PROVIDES ALL NECESSARY TOOLS AND SUPPORT TO MAXIMISE STUDENT POTENTIAL.