The Non-Calculator Paper: 10 Tactics That Actually Save Marks

The non-calculator paper is where most marks are lost not to lack of knowledge, but to arithmetic slips. These ten tactics are the ones we’ve watched students use to add 8–15 marks to their paper without learning a single new topic.

1. Re-derive, don’t memorise

If you’re not sure whether to multiply or divide, write the units. “20 miles in 30 minutes” → “miles per hour” = miles ÷ hours. The unit tells you the operation.

2. Estimate first, calculate second

For every multi-step question, jot a rough estimate before you start. 47 × 19 ≈ 50 × 20 = 1000. When you get an exact answer, check it’s near your estimate. A wildly off estimate means you’ve made an error somewhere.

Tip: Estimation feels slow when you’re under pressure, but it catches 80% of catastrophic mistakes (off by a factor of 10) in 5 seconds.

3. Column arithmetic, always

For any addition or subtraction with more than three digits or any decimals, switch to column method. Mental arithmetic is fast but error-prone. The exam doesn’t reward speed alone.

Method	Speed	Accuracy under pressure
Mental	Fast	~80%
Column on paper	Medium	~98%
Estimation + column	Medium-slow	~99%

4. The chunking method for division

Long division on paper is fine, but chunking is faster for most exam-style numbers. To do 187 ÷ 11:

• 11 × 10 = 110 (chunk 1, total: 110, remaining: 77)
• 11 × 7 = 77 (chunk 2, total: 187, remaining: 0)
• Answer: 10 + 7 = 17

Practise it on our Number quiz topics until it’s automatic.

5. Common fractions, decimals and percentages

Remember: These are the conversions worth memorising cold. They appear on every non-calculator paper, often as one-mark “freebies.”

Fraction	Decimal	Percentage
1/2	0.5	50%
1/4	0.25	25%
3/4	0.75	75%
1/5	0.2	20%
1/8	0.125	12.5%
1/10	0.1	10%
1/3	0.333…	33.3%
1/100	0.01	1%

6. Percentage shortcuts

Splitting a percentage in your head is way faster than the formula.

• 10% of anything: shift the decimal one place left.
• 5% = 10% halved.
• 20% = 10% doubled.
• 15% = 10% + 5%.
• VAT (20%) of £85: 10% = £8.50, double it = £17.

7. The “always check” five

Before you move on, eyeball every answer against this list:

1. Did I read the question correctly? (Underline the actual ask.)
2. Are my units right? (cm vs m, kg vs g.)
3. Is the magnitude sensible? (5p shouldn’t equal £50.)
4. Did I round correctly? (3 sig fig vs 3 decimal places — different rules.)
5. Did I write the final answer, not a working number?

8. Fractions: common denominators first

Don’t try to add 3/8 + 5/12 in one step. Convert both: LCM of 8 and 12 is 24. So:

• 3/8 = 9/24
• 5/12 = 10/24
• 9/24 + 10/24 = 19/24

Practise this on the Number app which has 25 subtopics on fractions alone.

9. BIDMAS, BIDMAS, BIDMAS

Brackets, Indices, Division/Multiplication, Addition/Subtraction.

The trap: 8 - 3 + 2 is 7, not 3. Division and multiplication tie at the same level (left to right). Same with addition and subtraction.

10. Time discipline

Did you know? The average grade-6 student finishes Paper 1 with 12 minutes to spare. They use those 12 minutes to check, not to wonder if they should attempt question 21 again.

Set this internal pace:

• Q1–10 (warm-up, 1-markers): 1 minute each → 10 mins
• Q11–20 (2–3 markers): 2 minutes each → 20 mins
• Q21+ (4–6 markers): 4–6 minutes each → 40 mins
• Final check: 20 mins

Real timing is messier — but if you finish Q20 by minute 30, you’re on track.

Practice these tactics

The only way these stick is repetition. Try our Number quiz — it draws from 79 subtopics across the full Foundation and Higher syllabus, and you can do 10 questions in a tea break.