Brilliant work, mate! You smashed it with 80%!

80% Grade 8 16 / 20 marks 25 min 0 sec
Question Breakdown
[email protected] Number — Standard form
0/2 marks

Write \( 0.0045 \) in standard form.

What Nova read: 45 × 10⁻⁴
What went wrong: 45 × 10⁻⁴ is numerically equal to 4.5 × 10⁻³, but it is not standard form because the coefficient must satisfy 1 ≤ A < 10 and 45 is out of range. No marks are awarded.
Tip: In A × 10ⁿ, always make sure A is between 1 and 10. For 0.0045, move the decimal 3 places right to get 4.5, giving 4.5 × 10⁻³.

Standard form is \( A \times 10^n \) where \( 1 \leq A < 10 \). Move the decimal point 3 places to the right to get \( 4.5 \): \( 0.0045 = 4.5 \times 10^{-3} \).

[email protected] Algebra — Equation of a straight line
2/3 marks
xy12312345(0, 1)(2, 5)

The graph shows a straight line. Find the equation of the line in the form \( y = mx + c \).

What Nova read: y = ½x + 1
What went wrong: The y-intercept is correct (c = 1), but the gradient is upside down. You used run ÷ rise (2 ÷ 4 = ½) instead of rise ÷ run (4 ÷ 2 = 2).
Tip: Gradient is always rise ÷ run: change in y over change in x. From (0, 1) to (2, 5) the line goes up 4 and across 2, so m = 4 ÷ 2 = 2, giving y = 2x + 1.

Gradient \( m = \frac{\text{rise}}{\text{run}} = \frac{5 - 1}{2 - 0} = \frac{4}{2} = 2 \).

The line crosses the \( y \)-axis at \( 1 \), so \( c = 1 \). The equation is \( y = 2x + 1 \).

[email protected] Geometry and Measures — Angles in a triangle
2/2 marks
55°80°x

The diagram shows a triangle. The diagram is not drawn accurately. Work out the size of angle \( x \).

The angles inside a triangle add up to \( 180° \).

\( x = 180° - 55° - 80° = 45° \).

[email protected] Geometry and Measures — Pythagoras' theorem
2/2 marks
8 cm6 cm?

The diagram shows a right-angled triangle. The diagram is not drawn accurately. Work out the length of the hypotenuse.

By Pythagoras' theorem, \( c^2 = a^2 + b^2 = 6^2 + 8^2 = 36 + 64 = 100 \).

\( c = \sqrt{100} = 10 \) cm.

[email protected] Statistics — Interpreting bar charts
2/2 marks
0246GoalsMonTueWedThuFri

The bar chart shows the number of goals a team scored on each day of a week. Work out the range of the number of goals scored.

The range is the highest value minus the lowest value.

Highest = 7 (Tuesday), lowest = 2 (Wednesday), so range \( = 7 - 2 = 5 \).

[email protected] Statistics — Interpreting pie charts
2/2 marks
120°FootballCricketOther

180 students were asked their favourite sport. The pie chart shows the results, and the angle for Football is \( 120° \). Work out the number of students whose favourite sport is Football.

The whole pie represents 180 students across \( 360° \).

Football \( = \frac{120}{360} \times 180 = \frac{1}{3} \times 180 = 60 \) students.

[email protected] Probability — Tree diagrams
2/2 marks
0.60.40.60.40.60.4HTHTHT

A biased coin has \( P(\text{Heads}) = 0.6 \). The tree diagram shows the coin being flipped twice. Work out the probability of getting two heads.

Multiply along the branches for Heads then Heads:

\( P(\text{H, H}) = 0.6 \times 0.6 = 0.36 \).

[email protected] Ratio, Proportion and Rates of Change — Distance-time graphs
1/2 marks
1206001234Time (hours)Distance (km)

The distance–time graph shows part of a car journey. Work out the speed of the car during the first 2 hours. Give the units of your answer.

What Nova read: 120 km
What went wrong: You read the distance travelled (120 km) correctly, but the question asks for the speed. Speed is not the same as distance — you still need to divide by the time.
Tip: Use speed = distance ÷ time = 120 km ÷ 2 h = 60 km/h. Watch for the units: a speed is measured in km/h here, not km.

Speed \( = \frac{\text{distance}}{\text{time}} = \frac{120}{2} = 60 \) km/h.

[email protected] Ratio, Proportion and Rates of Change — Sharing in a ratio
1/1 marks

Share £120 in the ratio \( 3 : 2 \). Work out the larger share.

Total parts \( = 3 + 2 = 5 \).

Larger share \( = \frac{3}{5} \times 120 = £72 \).

[email protected] Number — Reverse percentages
2/2 marks

In a sale, the price of a coat is reduced by 20%. The sale price is £64. Work out the original price of the coat.

The sale price is \( 100\% - 20\% = 80\% \) of the original price.

So \( 80\% = £64 \), which means original price \( = \frac{64}{0.8} = £80 \).