iGCSE Mathematics (0580) - C1.8 Standard form- Exam Style Questions Paper 3- New Syllabus
Question
Calculate
$\frac{4.6 \times 10^3}{1.84 \times 10^5}$
Give your answer in standard form.
Most-appropriate topic codes (Cambridge IGCSE Mathematics 0580):
▶️ Answer/Explanation
Divide the numerical parts and subtract the powers of $10$ separately:
$\frac{4.6}{1.84} = 2.5$
$\frac{10^3}{10^5} = 10^{3 – 5} = 10^{-2}$
Combine them to get the final answer in standard form.
✅ Answer: $2.5 \times 10^{-2}$
Question
Calculate $(5.6 \times 10^{-3}) \div (2.4 \times 10^{-5})$.
Write your answer in standard form.
Most-appropriate topic codes (Cambridge IGCSE Mathematics 0580):
▶️ Answer/Explanation
You can directly input this into a scientific calculator or process the numbers and indices separately.
$(5.6 \div 2.4) \times 10^{-3 – (-5)}$
$= 2.333… \times 10^{2}$
Rounding to an appropriate standard form gives $2.33 \times 10^2$.
✅ Answer: $2.33 \times 10^2$
(a) Work out \(48\div 3-5\times 2\).
(b) Insert one pair of brackets to make this statement correct.
3 + 2 × 12 – 4 = 19
(c) Write the following in order, starting with the smallest.
\(\frac{3}{4}\) 0.749 76%
(d) Find the value of: [1 each]
(i) \(\sqrt{265.69}\)
(ii) 83
(e) Write down the smallest prime number.
(f) Write down all the factors of 18.
(g) Write down a common factor of 16 and 72 that is greater than 2.
(h) Write \(\frac{28}{140}\) as a fraction in its simplest form.
(i) Jeff and his friends win a prize. Jeff’s share is \$160 which is \(\frac{5}{11}\) of the prize.
Work out the value of the prize.
▶️ Answer/Explanation
(a) Ans: 6
Using order of operations (BIDMAS):
\(48 ÷ 3 = 16\)
\(5 × 2 = 10\)
\(16 – 10 = 6\)
(b) Ans: 3 + 2 × (12 – 4) = 19
Brackets make the calculation:
\(12 – 4 = 8\)
\(2 × 8 = 16\)
\(3 + 16 = 19\)
(c) Ans: 0.749, \(\frac{3}{4}\), 76%
Convert all to decimals:
\(\frac{3}{4} = 0.75\)
76% = 0.76
Order: 0.749, 0.75, 0.76
(d)(i) Ans: 16.3
\(\sqrt{265.69} = 16.3\) (since \(16.3 × 16.3 = 265.69\))
(d)(ii) Ans: 512
\(8^3 = 8 × 8 × 8 = 512\)
(e) Ans: 2
2 is the smallest number with exactly two distinct factors (1 and itself).
(f) Ans: 1, 2, 3, 6, 9, 18
Numbers that divide 18 exactly: 1 × 18, 2 × 9, 3 × 6.
(g) Ans: 4 or 8
Common factors of 16 (1,2,4,8,16) and 72 (1,2,3,4,6,8,9,12,18,24,36,72) >2: 4, 8.
(h) Ans: \(\frac{1}{5}\)
Simplify \(\frac{28}{140}\): divide numerator and denominator by 28.
(i) Ans: \$352
Let total prize be \(x\):
\(\frac{5}{11}x = 160\)
\(x = 160 × \frac{11}{5} = 352\)
