# Math Revision for Grade 8

1. These five numbers are written in standard form.

4.5 × 105 8.7 × 10° 6.9 × 10-3 3.2 × 106 1.8 × 10-1 Arrange them in ascending order.

2. (a)Write 1.8 × 10-1as an ordinary number.(b) 4p × 45 = 415. Find the value of p.

3. Write 1.19886 correct to 3 significant figures.

4.(a) Which of the following does not equal the fraction 12/20 ? [pic]

(b). Simplify

[pic]

5. Hassan picks 24 kg of fruit.He finds that 8% of the fruit is rotten. Work out the mass of fruit which is rotten.

6. The population of a city is 550 000. It is expected that this population will increase by 42% by the year 2008. Calculate the expected population in 2008.

7. In triangle ABC, angle B is a right angle, angle A is equal to 45°, side AC = 20 cm. Find the length of side AB.

8.

[pic]

A, B and C are points on a circle, centre O.Angle AOB = 40°. (i) Write down the size of angle ACB. (ii) Find the size of angle OAB.

9. Find the hypotenuse of a right triangle with the other two sides measuring 3.2 cm and 2.4 cm.

10. Factorise the following

a) x2 + 8x + 15 (b)y2 – 15y+ 56

11.A railway line, between stations A and B, is straight and has a length of 4800 m. The bearing of B from A is 200 °. The point P is due east of B and due south of A.

[pic]

(a)Complete the sketch above to show triangle ABP.(b)Calculate the length of AP.

12.

[pic]

(a)Calculate the distance, OM, of the boy from the balloon. (b)Calculate angle MON.

13. In a triangle PQR, PQ = 12cm, QR = 1cm and PR = 13cm. Check whether this is a right triangle or not.

14.AD is a diameter of the circle...

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