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Cambridge Lower Secondary Maths: Stage 7

Stage 7 of the Cambridge Lower Secondary Mathematics (0862) curriculum framework, usually Year 7 (ages 11 to 12). Here is what each part asks, a practice question for each, and the mistakes that cost the most marks.

Practise Stage 7 as a game

The 60 parts of Stage 7

Each part with one practice question, made by the same engine your child plays.

Integers, powers and roots

Estimate, add and subtract integers

33 − 51 = ?

  1. 18
  2. −84
  3. 84
  4. −18
Show the answer

−18. Start at 33 and count down 51: you land on −18.

The order of brackets, positive indices and operations

(2 + 8) × 3 = ?

  1. 30
  2. 13
  3. 26
  4. 14
Show the answer

30. Brackets first: 2 + 8 = 10. Then 10 × 3 = 30.

Multiply and divide integers, one of them negative

16 ÷ (−4) = ?

  1. 8
  2. 12
  3. 4
  4. −4
Show the answer

−4. 16 ÷ 4 = 4. The signs are different, so the answer is negative. −4.

Lowest common multiple and highest common factor, numbers under 100

Find the LCM of 12 and 15.

  1. 180
  2. 60
  3. 27
  4. 30
Show the answer

60. Multiples of 15: the first one that 12 also divides is 60.

Use tests of divisibility to find factors of numbers above 100

Which of these is a factor of 616?

  1. 11
  2. 10
  3. 6
  4. 9
Show the answer

11. 616 divides by 11 because the alternating sum of its digits is 0 or a multiple of 11: 616 ÷ 11 = 56.

Squares and square roots, cubes and cube roots, as inverses

15² = 225.
So what is √225?

  1. 15
  2. 112.5
  3. 16
  4. 225
Show the answer

15. Squaring and taking the square root undo each other: 15² = 225, so √225 = 15.

Place value, ordering and rounding

Multiply and divide whole numbers and decimals by any positive power of 10

0.31 × 1,000 = ?

  1. 310
  2. 31000
  3. 3.1
  4. 31
Show the answer

310. Multiplying by 1,000 moves each digit 3 places to the left.

Round to a given number of decimal places

Round 17.717 to 2 decimal places.

  1. 17.71
  2. 17.74
  3. 17.72
  4. 18.72
Show the answer

17.72. Keep 2 digits after the point and look at the next one, 7: it rounds up. 17.72.

Fractions, decimals, percentages, ratio and proportion

Fractions, terminating decimals and percentages can be equal

Write 7/10 as a percentage.

  1. 7%
  2. 30%
  3. 70%
  4. 80%
Show the answer

70%. 7/10 = 70/100 = 70%.

Add mixed numbers; answer as a mixed number in simplest form

1/6 + 3/4 = ?
(simplest form)

  1. 1/6
  2. 1/8
  3. 2/5
  4. 11/12
Show the answer

11/12. Use 24 as the denominator: 4/24 + 18/24 = 11/12.

Multiply and divide proper fractions

1/3 ÷ 5/6 = ?

  1. 5/18
  2. 2/5
  3. 5/2
  4. 2/3
Show the answer

2/5. Flip the second fraction and multiply: 1/3 × 6/5 = 2/5.

Simplify calculations with decimals or fractions using factors, laws and order of operations

Work out 5 × 20 × 20 the easy way.

  1. 2010
  2. 2000
  3. 120
  4. 1990
Show the answer

2000. Multiplying can be done in any order: 5 × 20 = 100 first, then 100 × 20 = 2000.

Percentages of shapes and numbers, including below 1% and above 100%

What is 15% of 1160?

  1. 116
  2. 232
  3. 1145
  4. 174
Show the answer

174. 10% of 1160 is 116 and 5% is 58. Build 15% from those: 174.

Compare and order decimals and fractions with =, ≠, > and <

Which statement is true?

  1. 7.5 < 7.44
  2. 7.44 > 7.5
  3. 7.5 > 7.44
  4. 7.44 = 7.5
Show the answer

7.5 > 7.44. Write both with two decimal places: 7.50 and 7.44. 7.5 is bigger, even if it has fewer digits.

Add and subtract positive and negative decimals

8.9 − −1.7 = ?

  1. 7.2
  2. 10.6
  3. −7.2
  4. −10.6
Show the answer

10.6. Taking away a negative is the same as adding: 8.9 + 1.7 = 10.6.

Multiply and divide decimals by whole numbers

0.4 × 0.7 = ?

  1. 2.8
  2. 0.28
  3. 0.028
  4. 1.1
Show the answer

0.28. 4 × 7 = 28. Two decimal places in the question, so 0.28.

The unitary method for ratio and direct proportion

y is inversely proportional to x.
When x = 3, y = 8.
Find y when x = 8.

  1. 8
  2. 3
  3. 21.3
  4. 4
Show the answer

3. y = k ÷ x. From the first pair, k = 8 × 3 = 24. So y = 24 ÷ 8 = 3.

Simplify and compare ratios in the same units

Drink A mixes juice and water 3:5. Drink B mixes them 4:2.
Which drink is MORE juicy?

  1. They are the same
  2. You cannot compare different ratios
  3. Drink B
  4. Drink A
Show the answer

Drink B. Compare the share that is juice: A is 3/8 = 37.5%, B is 4/6 = 66.7%. Drink B has more juice.

Divide an amount in a ratio with two parts

$30 is shared in the ratio 1 : 4.
How much is the larger share?

  1. $26
  2. $6
  3. $24
  4. $7.5
Show the answer

$24. 1 + 4 = 5 parts. One part is 30 ÷ 5 = 6. The larger share is 4 × 6 = 24.

Expressions, equations and formulae

Letters can stand for unknowns, variables or constants

In y = 2x + 1, what is the letter x?

  1. Always the number 1
  2. A variable: it can take many values
  3. An unknown: one value makes it true
  4. A label for a unit, like cm
Show the answer

A variable: it can take many values. An EQUATION like 3x + 2 = 17 has one answer: x is an unknown to find. A FORMULA like y = 2x + 1 links two quantities: x can be anything, and y follows.

The laws of arithmetic and the order of operations apply to algebra

Which is the same as x × 7 × y?

  1. 7x + 7y
  2. 7xy
  3. 7 + xy
  4. 7x + y
Show the answer

7xy. Multiplication can be done in any order (commutative): x × 5 × y = 5xy.

Collect like terms; multiply a bracket by a constant

Expand
2n(2n − 2)

  1. 4n² − 4n
  2. 4n − 4n
  3. 4n² − 4
  4. 4n² − 2
Show the answer

4n² − 4n. Multiply BOTH terms inside by 2n: 2n × 2n = 4n², and 2n × 2 = 4n.

A situation in words or as a linear expression

Aisha has p stickers.
They are shared equally between 3 friends, and then each friend gets 4 more.
Which expression is one friend's number?

  1. (p + 4)/3
  2. p/3 + 4
  3. p/7
  4. 3p + 4
Show the answer

p/3 + 4. Sharing between 3 is p/3. Then 4 more each: p/3 + 4.

A situation in words or as a one-step formula

A regular shape has 6 equal sides, each s cm long.
Which formula gives its perimeter P?

  1. P = s⁶
  2. s = 6P
  3. P = 6s
  4. P = s + 6
Show the answer

P = 6s. 6 sides of s cm each: P = 6 × s = 6s.

A situation in words or as an equation; solve it (unknown on one side)

I think of a number.
I multiply it by 5 and then add 4.
The answer is 14. What was my number?

  1. 4
  2. 10
  3. 2
  4. 50
Show the answer

2. The equation is 5n + 4 = 14. Take 4 away: 5n = 10. Divide by 5: n = 2.

A letter can stand for an open interval (one term)

How many integers satisfy
−2 < x ≤ 1 ?

  1. 3
  2. 2
  3. 4
  4. 8
Show the answer

3. From −1 up to 1: that is 3 integers. < leaves the end number out, ≤ keeps it.

Sequences, functions and graphs

Term-to-term rules; generate linear sequences from numbers and patterns

3, 10, 17, 24, …
Which is the term-to-term rule?

  1. add 7
  2. multiply by 3
  3. add 3
  4. add 8
Show the answer

add 7. Each term is 7 more than the one before: 3 + 7 = 10, 10 + 7 = 17.

nth term rules of the form n ± a and a × n

Find the nth term.
1, 6, 11, 16, …

  1. 5n − 4
  2. 5n + 1
  3. n + 5
  4. 5n + 4
Show the answer

5n − 4. It goes up in 5s, so it starts 5n. When n = 1, 5n = 5, and the first term is 1: adjust by −4.

A function gives one output for each input; find outputs, and inputs by inverse operations

A function machine: input → × 6 → + 2 → output.
The OUTPUT is 20. What was the input?

  1. 3.666667
  2. 1.333333
  3. 3
  4. 122
Show the answer

3. Run the machine backwards, undoing each step in reverse: 20 − 2 = 18, then ÷ 6 = 3.

A situation in words or as a linear function (y = x + c, y = mx)

A plumber charges C = 8h + 9, where h is the number of hours.
What does the formula say in words?

  1. $8 to come out, plus $9 for every hour
  2. $17 for every hour
  3. $9 to come out, plus $8 for every hour
  4. $72 for the job
Show the answer

$9 to come out, plus $8 for every hour. The 8 is multiplied by h, so it is paid for EACH hour. The + 9 is paid once, whatever the hours.

Tables of values and graphs of y = x + c and y = mx

A point on the line y = x + 2 has x = 3.
What are its coordinates?

  1. (3, 1)
  2. (3, 6)
  3. (3, 5)
  4. (5, 3)
Show the answer

(3, 5). Put x = 3 into the equation: y = 5. The point is (3, 5): x first, then y.

Straight lines parallel to the x- or y-axis

Which point lies on the line x = 1?

  1. (0, 0)
  2. (−1, 1)
  3. (2, 2)
  4. (1, −1)
Show the answer

(1, −1). Every point on x = 1 has x-coordinate 1, whatever the other one is. (1, −1) does.

Read and interpret graphs of rates of change, and explain their shape

On a graph of water in a bath against time, the line goes DOWN.
What does that show?

  1. Water is going out: the bath is emptying
  2. The water is getting hotter
  3. The bath is filling
  4. Nothing is happening
Show the answer

Water is going out: the bath is emptying. Read the axes first. Flat means no change; steeper means faster change; going down means the quantity is getting smaller.

Geometrical reasoning, shapes and measurements

Regular polygons: sides, angles and symmetry

A regular polygon has rotational symmetry of order 8.
How many sides does it have?

  1. 16
  2. 45
  3. 8
  4. 10
Show the answer

8. A regular polygon with n sides has n lines of symmetry and rotational symmetry of order n. Here n = 8.

Congruent shapes have equal corresponding sides and angles

Triangles ABC and PQR are congruent:
A matches P, B matches Q and C matches R.
AB = 6 cm, BC = 7 cm and AC = 8 cm. How long is QR?

  1. 8 cm
  2. 7 cm
  3. 5 cm
  4. 6 cm
Show the answer

7 cm. Congruent shapes are identical, so matching sides are equal. QR matches BC: 7 cm.

Parts of a circle, including chord and tangent

The radius of a circle is 12 cm.
How long is its diameter?

  1. 24 cm
  2. 144 cm
  3. 14 cm
  4. 6 cm
Show the answer

24 cm. A diameter is two radii: 2 × 12 = 24 cm.

Convert between metric units of area, including hectares

Convert 5 litres to cm³.

  1. 500
  2. 50,000
  3. 5,000
  4. 500,000
Show the answer

5,000. 1 litre = 1000 cm³. 5 × 1,000 = 5,000.

Area of a triangle, and of compound shapes made of rectangles and triangles

A triangle has base 40 cm and height 22 cm.
What is its area?

  1. 880 cm²
  2. 440 cm²
  3. 124 cm²
  4. 62 cm²
Show the answer

440 cm². Area = ½ × base × height = ½ × 40 × 22 = 440 cm².

The properties that fix a particular 3D shape

A solid has 6 faces, 10 edges and 6 vertices.
Which solid could it be?

  1. pentagonal pyramid
  2. pentagonal prism
  3. cube
  4. square-based pyramid
Show the answer

pentagonal pyramid. A pentagonal pyramid has 6 faces, 10 edges and 6 vertices. (square-based pyramid: 5, 8, 5.)

Volume of cubes and cuboids, and of compound shapes made from them

A cuboid measures 3 cm by 4 cm by 11 cm.
Find its volume.

  1. 132 cm³
  2. 18 cm³
  3. 178 cm³
  4. 12 cm³
Show the answer

132 cm³. 3 × 4 × 11 = 132 cm³.

Front, side and top views of 3D shapes

The questions for this part come with a picture or are played as a game, so they are best tried in Huh Lab.

Surface area of cubes and cuboids

Find the total surface area of a 9 cm by 2 cm by 2 cm cuboid.

  1. 80 cm²
  2. 40 cm²
  3. 36 cm²
  4. 52 cm²
Show the answer

80 cm². Three different faces: 18, 18 and 4 cm². There are two of each: 2 × 40 = 80 cm².

Reflective symmetry and order of rotational symmetry

The questions for this part come with a picture or are played as a game, so they are best tried in Huh Lab.

Angles in a quadrilateral add to 360°; find the missing one

The questions for this part come with a picture or are played as a game, so they are best tried in Huh Lab.

Angles around a point add to 360°; find the missing one

The questions for this part come with a picture or are played as a game, so they are best tried in Huh Lab.

Angles on parallel lines and transversals, perpendicular and intersecting lines

Two parallel lines are crossed by a third line.
One angle is 115°. What is its alternate angle?

  1. 245°
  2. 115°
  3. 25°
  4. 65°
Show the answer

115°. Alternate angles (the Z shape) are equal: 115°.

Position and transformation

Use scale to interpret maps and plans

A map has a scale of 1 : 100,000.
A road is 4 km long. How long is it on the map?

  1. 40 cm
  2. 4 cm
  3. 5 cm
  4. 0.4 cm
Show the answer

4 cm. 4 km = 400,000 cm. Divide by 100,000: 4 cm on the map.

Distance between two coordinates that share an x or a y

Find the distance between (−6, −3) and (7, −3).

  1. 7
  2. 12
  3. 13
  4. 1
Show the answer

13. The y-coordinates are the same, so the points are on a line across the page. The distance is the gap in the OTHER coordinate: 7 − (−6) = 13.

Corresponding points under a translation, without a grid

A translation takes P (8, 4) to (10, 9).
Where does the same translation take Q (9, 5)?

  1. (19, 14)
  2. (11, 10)
  3. (7, 0)
  4. (14, 7)
Show the answer

(11, 10). P moved 2 in x and 5 in y. Every point moves the same way, so Q goes to (11, 10).

Reflect shapes in the x- or y-axis; the image is congruent

The point (3, 5) is
reflected in the line y = x.
Where is its image?

  1. (−3, 5)
  2. (5, 3)
  3. (−3, −5)
  4. (−5, 3)
Show the answer

(5, 3). x and y swap places.

Rotate shapes 90° and 180° about a centre; the image is congruent

The point (4, −1) is
rotated 180° about the origin.
Where is its image?

  1. (−1, 4)
  2. (1, 4)
  3. (−4, 1)
  4. (−4, −1)
Show the answer

(−4, 1). Both coordinates change sign.

Enlarge by a positive whole-number scale factor; the image is similar

The point (6, 2) is enlarged with centre (0, 0)
and scale factor 2. Where does it go?

  1. (8, 4)
  2. (12, 4)
  3. (12, 2)
  4. (6, 4)
Show the answer

(12, 4). From the origin, multiply BOTH coordinates by 2: (12, 4).

Statistics

The effect of sample size

Which statement about samples is true?

  1. A sample can tell you nothing about the population.
  2. A larger sample gives results closer to the whole population, but costs more time and money.
  3. A sample of 10 is always as good as a sample of 1,000.
  4. Doubling a sample makes its results twice as accurate.
Show the answer

A larger sample gives results closer to the whole population, but costs more time and money.. Bigger samples are more reliable, but there is a trade-off: they take longer and cost more. That is why a sample is used at all, instead of asking everyone.

Record and show data: Venn, Carroll, two-way tables, dual and compound bar charts, waffle and pie charts, frequency diagrams, line and scatter graphs, infographics

The questions for this part come with a picture or are played as a game, so they are best tried in Huh Lab.

Use mode, median, mean and range on large data sets, and choose the most suitable

A shop wants to know which shoe size to stock most of.
Which average is most suitable?

  1. The range
  2. The mean
  3. The median
  4. The mode
Show the answer

The mode. It is the size most people wear; the mean could be a size nobody wears.

Interpret patterns within and between data sets; check predictions

The questions for this part come with a picture or are played as a game, so they are best tried in Huh Lab.

Probability

Describe, compare and order likelihoods in the language of probability

An event has probability 0.9.
In words, it is…

  1. unlikely
  2. an even chance
  3. impossible
  4. likely
Show the answer

likely. Probability runs from 0 (impossible) through ½ (an even chance) to 1 (certain).

Probabilities run from 0 to 1, as fractions, decimals or percentages

Where on the probability scale from 0 to 1 is an event that is likely?

  1. 0.8
  2. 0
  3. 1
  4. 0.5
Show the answer

0.8. Probabilities run from 0 (impossible) to 1 (certain), with 0.5 an even chance in the middle.

List all the mutually exclusive outcomes of one event; are they equally likely?

A fair dice is rolled once.
Which list shows ALL the possible outcomes?

  1. 1, 2, 3, 4, 5, 6
  2. odd, even, 6
  3. 6
  4. 1, 2, 3
Show the answer

1, 2, 3, 4, 5, 6. A dice can show any of 1, 2, 3, 4, 5 or 6, and nothing else. Those six outcomes are equally likely.

Theoretical probability of equally likely outcomes

A bag holds 3 red and 1 blue balls.
One is picked at random.
What is the probability it is red?

  1. 4/5
  2. 1/4
  3. 3/4
  4. 1/3
Show the answer

3/4. 3 red out of 4 balls altogether: 3/4.

The mistakes that cost the most marks

Huh Lab checks every wrong answer against known mistakes like these, and goes back to the step behind the one your child keeps making.

Loses the negative sign

Use a number line: below zero the numbers keep counting, in the other direction.

Gets the end number wrong

< and > leave the end number OUT. ≤ and ≥ keep it in. Check each end separately.

Gives the y-coordinate first

Along the corridor, THEN up the stairs: x comes before y.

Reflects in the wrong direction

A reflection goes straight ACROSS the mirror line, never along it.

Scales area by the length factor

Lengths × 3 means areas × 9 and volumes × 27. Square or cube the scale factor.

Adds the denominators too

Quarters plus quarters are still quarters. Only the tops are added.

Forgets to halve for a triangle

A triangle is half of the rectangle around it.

Reads the angle as the number of people

The angle is a share of 360°. Turn it into a fraction of the whole first.

Other Cambridge Lower Secondary Maths stages

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