Foundation November 2021 Paper 2 Q19
19 Work out which of these fractions is closer in value to 0.5
\(\dfrac{5}{16} \qquad\qquad \dfrac{17}{25}\)
You must show your working. [2 marks]
| Answer | Mark | Comments |
|---|---|---|
| Alternative method 1 | ||
| 0.31(25) or 0.68 | M1 | oe eg 31(.25)% or 68% |
| 0.31(25) and 0.68 and \(\dfrac{17}{25}\) | A1 | accept 0.68 as the answer with both values seen |
| Alternative method 2 | ||
| Converts both fractions to a valid common denominator with at least one numerator correct | M1 | eg \(\dfrac{125}{400}\) and \(\dfrac{272}{400}\) with one numerator correct |
| Two correct fractions with a common denominator and \(\dfrac{17}{25}\) | A1 | accept \(\dfrac{272}{400}\) oe as the answer with both values seen |
| Alternative method 3 | ||
| Gives differences from \(\dfrac{1}{2}\) in same form with at least one correct | M1 | eg \(\dfrac{75}{400}\) and \(\dfrac{72}{400}\) with one numerator correct or 0.1875 and 0.18 with one correct |
| Both differences correct and \(\dfrac{17}{25}\) | A1 | accept 0.18 as the answer with both values seen |
Additional guidance
Accept \(\dfrac{17}{25}\) circled in question with both values seen
Ignore subsequent rounding or truncation once 0.31 and 0.68 seen
Ignore incorrect attempts at differences in Alt 1 and Alt 2 and award up to full marks
Choose the scheme that favours the student
Use of other methods requires comparable forms
eg \(0.5 - \dfrac{5}{16} = \dfrac{3}{16}\), \(0.5 + \dfrac{3}{16} = \dfrac{11}{16}\) and compares with \(\dfrac{17}{25}\)