Find √(5.76)
Using a calculator — Notes & Worked Examples Show / Hide
Explanation:
When evaluating a complex fraction or root on a scientific calculator, press the fraction button (□□) first so the display matches the printed question, or put brackets around the entire numerator and denominator: (top) ÷ (bottom).
In GCSE exams, always write down the full calculator display (or at least the first 6 digits) as your first line of working before rounding to the requested number of decimal places or significant figures.
Example 1: Use your calculator to work out
14.8 + 7.65.2 − 1.72.
Give your answer to 2 decimal places.
Solution:
• Numerator: 14.8 + 7.6 = 22.4
• Denominator: 5.2 − 2.89 = 2.31
• Full display: 22.4 ÷ 2.31 = 9.6969696…
• Round to 2 d.p. → Answer: 9.70
Example 2: Work out √(8.52 + 4.23)3.1 correct to 3 significant figures.
Solution:
• Inside square root: 72.25 + 74.088 = 146.338
• Numerator: √146.338 = 12.097024…
• Full display: 12.097024… ÷ 3.1 = 3.9022659…
• Round to 3 s.f. → Answer: 3.90
Work out the value of 9.75 - 1.429.2 + √(6.3)
Write down all the figures on your calculator display.
Write down all the figures on your calculator display.
Worked Solution & Answer
Find the value of 5.27 + 3.57.9 - 4.36
Give your answer as a decimal.
Write down all the figures on your calculator display.
Give your answer as a decimal.
Write down all the figures on your calculator display.
Worked Solution & Answer
8.77 ÷ 3.54 = 2.4774011299... M1 A1
Answer: 2.4774011(299...)
Work out the value of 5.22 + 8.7√(14.5)
Write down all the figures on your calculator display.
Write down all the figures on your calculator display.
Worked Solution & Answer
(27.04 + 8.7) ÷ 3.80788655... = 35.74 ÷ 3.80788655... = 9.3857894... M1 A1
Answer: 9.3857894
Work out 2.75 × 14.610 - 1.97
Worked Solution & Answer
Find the value of √(13.4 - 1.5)(6.8 + 0.06)2
Write down all the figures on your calculator display.
Write down all the figures on your calculator display.
Worked Solution & Answer
√11.9 ÷ 6.86² = 3.449637662 ÷ 47.0596 = 0.07330359079... M1 A1
Answer: 0.07330359...
Use your calculator to work out the value of
17.98.61 + 2.36 - 1.22
Give your answer as a decimal.
Write down all the figures on your calculator display.
17.98.61 + 2.36 - 1.22
Give your answer as a decimal.
Write down all the figures on your calculator display.
Worked Solution & Answer
17.9 ÷ 10.97 − 1.44 = 1.63172288... − 1.44 = 0.1917228806 M1 A1
Answer: 0.1917228806
Use your calculator to work out
3√(1.574 + \tan 60°)7.2\tfrac{1}{2}
Give your answer correct to 3 significant figures.
3√(1.574 + \tan 60°)7.2\tfrac{1}{2}
Give your answer correct to 3 significant figures.
Worked Solution & Answer
1.57⁴ + tan 60° = 6.0757... + 1.73205... = 7.80778... M1
∛7.80778... = 1.98385...
√7.2 = 2.68328...
1.98385 ÷ 2.68328 = 0.7393... → 0.739 A1
∛7.80778... = 1.98385...
√7.2 = 2.68328...
1.98385 ÷ 2.68328 = 0.7393... → 0.739 A1
Answer: 0.739
Use your calculator to work out the value of
√(<span class="opg-frac"><span class="opg-num">208.3 - 15.7</span><span class="opg-den">5.694 + 1.8<sup>2</sup></span></span>)
Write down all the digits on your calculator display.
√(<span class="opg-frac"><span class="opg-num">208.3 - 15.7</span><span class="opg-den">5.694 + 1.8<sup>2</sup></span></span>)
Write down all the digits on your calculator display.
Worked Solution & Answer
√(192.6 / 8.934) = √21.55809268 = 4.643069317 M1 A1
Answer: 4.643069317
Abi has some £10 notes and some £20 notes.
The notes have a total value of £400
Abi has six £20 notes.
The notes have a total value of £400
Abi has six £20 notes.
Work out the number of £10 notes Abi has.
Worked Solution & Answer
Value of £20 notes = 6 × £20 = £120 M1
Remaining value in £10 notes = £400 – £120 = £280 M1
Number of £10 notes = 280 ÷ 10 = 28. A1
Remaining value in £10 notes = £400 – £120 = £280 M1
Number of £10 notes = 280 ÷ 10 = 28. A1
Answer: 28