Hint
Use the stated units and precision. Compare signed values on a number line.
Worked solution
(a)
The two negative values come first, with −B less than −A because B>A>0.
Answer: \(\displaystyle - \frac{4}{5}\) < \(\displaystyle - \frac{3}{5}\) < \(\displaystyle \frac{3}{5}\) < \(\displaystyle \frac{4}{5}\)
(b)
Choose the rightmost value.
\(\displaystyle \frac{4}{5}\)
Answer: \(\displaystyle \frac{4}{5}\)
(c)
Subtract the negative smallest value from the positive largest.
\(\displaystyle \frac{8}{5}\)
Answer: \(\displaystyle \frac{8}{5}\)
Maths4U indicative marking guidance
Maths4U indicative marking guidance, not an official mark scheme. Credit complete valid alternative methods and consequential reasoning. An unexplained result does not earn a method mark.
(a) · 2 marks
- 1 mark: Convert the values to comparable exact forms and account for their signs.
- 1 mark: Give the complete requested result, using the required units, precision and boundary inclusion.
Alternative methods: Any complete mathematically valid alternative method with the same restrictions and equivalent exact result is acceptable.
Common error: Keep intermediate values exact until the final step.
(b) · 2 marks
- 1 mark: Choose the rightmost value.
- 1 mark: Give the correct requested result, retaining signs, units and any domain restrictions.
Alternative methods: Any complete mathematically valid alternative method with the same restrictions and equivalent exact result is acceptable.
Common error: Check the answer against the original conditions.
(c) · 2 marks
- 1 mark: Subtract the negative smallest value from the positive largest.
- 1 mark: Give the correct requested result, retaining signs, units and any domain restrictions.
Alternative methods: Any complete mathematically valid alternative method with the same restrictions and equivalent exact result is acceptable.
Common error: Keep intermediate values exact until the final step.
Total: 6 marks.