IGCSE · Mathematics 0580 · Number

Surds: IGCSE Mathematics questions with answers

Free Surds questions for IGCSE Mathematics (0580), Extended tier (Supplement content), part of Number. Each question has the answer and the marking points an examiner would look for.

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Surds practice questions

Question 1Structured · 3 marksA* challenge

Write the recurring decimal 0.2757575… (the digits 75 recur) as a fraction in its simplest form.
Show all your working.

[3]
Show answers and mark scheme
PartAnswer and marking pointsMarks
91330
e.g. 1000x = 275.7575… and 10x = 2.7575… M1
990x = 275 − 2 = 273 M1
91330 A1
3
Question 2Structured · 6 marksA* challenge
(a)

Expand and simplify (3 + 2√7)2.

[2]
(b)

Hence, or otherwise, simplify √(37 + 12√7).

[1]
(c)

Rationalise the denominator and simplify −193 + 2√7.

[3]
Show answers and mark scheme
PartAnswer and marking pointsMarks
(a)37 + 12√7
three or four correct terms M1
37 + 12√7 A1
2
(b)3 + 2√7
3 + 2√7 B1
1
(c)3 − 2√7
multiply by 3 − 2√73 − 2√7 M1
denominator −19 A1
3 − 2√7 A1
3
Question 3Structured · 3 marks

Without using a calculator, work out 116 ÷ 312.
Show all your working and give your answer as a mixed number in its simplest form.

[3]
Show answers and mark scheme
PartAnswer and marking pointsMarks
13
76 and 72 seen B1
76 × 27 M1
13 A1
3
Question 4Structured · 3 marksA* challenge

Write 5 + √235 − √23 in the form a + b√23, where a and b are integers.
Show all your working.

[3]
Show answers and mark scheme
PartAnswer and marking pointsMarks
24 + 5√23
× 5 + √235 + √23 M1
numerator 48 + 10√23, denominator 2 A1
24 + 5√23 A1
3
Question 5Structured · 3 marksA* challenge

Write the recurring decimal 0.6151515… (the digits 15 recur) as a fraction in its simplest form.
Show all your working.

[3]
Show answers and mark scheme
PartAnswer and marking pointsMarks
203330
e.g. 1000x = 615.1515… and 10x = 6.1515… M1
990x = 615 − 6 = 609 M1
203330 A1
3
Question 6Structured · 6 marksA* challenge
(a)

Expand and simplify (5 + 3√2)2.

[2]
(b)

Hence, or otherwise, simplify √(43 + 30√2).

[1]
(c)

Rationalise the denominator and simplify 75 + 3√2.

[3]
Show answers and mark scheme
PartAnswer and marking pointsMarks
(a)43 + 30√2
three or four correct terms M1
43 + 30√2 A1
2
(b)5 + 3√2
5 + 3√2 B1
1
(c)5 − 3√2
multiply by 5 − 3√25 − 3√2 M1
denominator 7 A1
5 − 3√2 A1
3

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Original Cambridge-style practice questions written for mentorriyaz.in. These are not Cambridge past paper questions, and this site is not affiliated with or endorsed by Cambridge University Press & Assessment. Updated 2026-11-04. Paper generator · mentorriyaz.in