Revision y9
1- Work out the following:
a. 23×2
b. 24 ÷ 20
c. 22 x 23
d. 2 × 10−1
e. 0.02 × 104
f. 2 ÷ 10−4
g. 0.5 ÷ 103
2
4
h. 3 ÷ 2 9
4
3
i. 3 × 2 × 4
j.
(2.6−1.2)2
0.4
k. (24 ÷ 10−2 ) − (4 × 103 )
2- Complete the following
a. 2.5 × 101 × 10…?… = 2500
b. ……?.......× … … . ? … … = 12 ( 𝑢𝑠𝑒 𝑜𝑛𝑙𝑦 𝑛𝑒𝑔𝑎𝑡𝑖𝑣𝑒 𝑛𝑢𝑚𝑏𝑒𝑟 𝑡𝑜 𝑓𝑖𝑙𝑙 𝑡ℎ𝑒 𝑏𝑙𝑎𝑛𝑘)
c. 0.45 × … … . . = 450
d. 4500 ÷ … … … . . = 45
e. … … … .× 100 = 4.5
3- Round the following
a. 259753 (to the nearest thousand)
b. 56.646 (to one decimal place)
c. 2456 (to the nearest hundred)
d. 2.546 (to two decimal places)
e. Use the calculator to find the square root 54. (then round to one decimal place)
4- Solve and simplify the following
a.
2𝑎5 ×4𝑎7 ×6𝑎2
(simplify)
2𝑎3 ×2𝑎6
b. (𝑥 + 2)(𝑥 + 7)
( expand and simplify)
10
c. 3−2𝑥 = −4
( solve the equation)
d. 6(6 − 4𝑥) = 4𝑥 − 22
e. 𝑦 = 4𝑥 − 10
( solve the equation)
10𝑥 − 4𝑦 = 28
( solve the simultaneous equation by substitution)
5- Change the subject
a. 𝑦 =
2𝑥
𝑤
b. 𝑦 = 2𝑥 − 2
c. √𝑥 = 𝑦 − 2
( make x the subject)
(make x the subject)
( make y the subject)
6- Solve the following inequalities.
a. 4 less than twice a number is greater than or equal to 12. Write an inequality and solve it.
b. Tom thinks of a number, he multiplies it by 2. His answer is greater than -4 and less than
or equal to 10. Write an inequality and solve it.
b. 38 ≤ 14 − 6𝑥
solve the inequality and draw it on the number line.
7- Substitute the following
a. 𝐴 =
𝜋𝑟𝑠2
when r= 2.5
4
b. 5(𝑥 − 1)4
b=4.2
when x= 3
8- Find the value of angle x
9-
10.5
514
2.3
Find the volume of the given cuboid.
10- Write an expression for the area and perimeter.
y
5
( use the calculator)
11- The diagram shows two parallel lines and two transversals.
Show all the angles that are equal to 50.
12-
a. For the given polygon, find the value of the angles x and y.
b. For the given polygon, find the value of x.
13- Find the following:
a. interior angle of a regular pentagon.
b. sum of interior angles of a decagon.
c. interior angle of a regular hexagon.
d. sum of interior angles of a 7-sided polygon.
e. exterior angle of a regular hexagon.
f. exterior angle of a regular pentagon.
g. interior angle of an equilateral triangle.
14a. Simplify the ratio 24:60
b. A student has 45 pencils and 25 pens. Write the ratio of pencils: pens in its simplest form.
He wants to keep the ratio of pencils: pens as 5:4. He kept his 45 pencils but buy some more
pens. Work out the number of pens he must buy.
c. Angelina has yellow and blue marbles in the ratio 2:5. The total number of her marbles is
42.
Her friend Sofia also has yellow and blue marbles in the ratio 3:2. If they each have the same
number of yellow marbles. Find the total number of marbles that Sofia has.
15- A car travels 120km in 3hours. How many km will it cover in 5hrs?
16- It took 12 people 4 hours to wash a hall. How many minutes would it take 20 people to
wash the hall?
17- A dress costs $42.5. the price of the dress is increased by 4% and then increased again by
12.5%. find the new price of the dress.
18- Karen buys a car that costs $8000 and she sell it by $7500. Find the percentage loss.
19- If n is a whole number. Find different values on n for the expression
expression a recurring decimal.
20- a. Write 90000 in standard form.
b. Write 7.5 × 10−3 as an ordinary number.
21- Write as a single fraction.
2 1
1
+
+
𝑦 3𝑦 4
22- Write rational or irrational.
a. √17
b. 72
c. 𝜋
38
d. 12
23- Estimate the square root of the following
a. √11
b. √22
c. √34
d. √30
c. √12
1
𝑛
to make the
24- The perimeter of a square where the length of each side has been measured at 82 meter
when rounded to the nearest meter. Find the difference between the upper and lower limit
of the length of the square.
25- A number x is rounded to the nearest 10 is 1200.
Use an inequality to represent the upper and lower bounds.
26- Find the upper and lower bounds for the number 247.24
a. When rounded to the nearest hundredth
b. When rounded to the nearest tenth
c. When rounded to 1dp
d. When rounded to 2dp
27- Find the upper and lower bounds for the number 1600
a. When rounded to the nearest tens.
b. When rounded to the nearest hundreds.