Hint
Use the stated units and precision. Replace the exact decimals by fractions with powers of ten, perform the operation and simplify.
Worked solution
(a)
Replace the exact decimals by fractions with powers of ten, perform the operation and simplify.
\(\displaystyle \frac{23}{20}\)
Answer: \(\displaystyle \frac{23}{20}\)
(b)
Replace the exact decimals by fractions with powers of ten, perform the operation and simplify.
\(\displaystyle \frac{21}{20}\)
Answer: \(\displaystyle \frac{21}{20}\)
(c)
Replace the exact decimals by fractions with powers of ten, perform the operation and simplify.
\(\displaystyle \frac{11}{200}\)
Answer: \(\displaystyle \frac{11}{200}\)
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: Replace the exact decimals by fractions with powers of ten, perform the operation and simplify.
- 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.
(b) · 2 marks
- 1 mark: Replace the exact decimals by fractions with powers of ten, perform the operation and simplify.
- 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: Replace the exact decimals by fractions with powers of ten, perform the operation and simplify.
- 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.