iGCSE Mathematics (0580) : C1.9 Make estimates of numbers, quantities and lengths, give approximations to specified numbers of significant figures. iGCSE Style Questions Paper 3

Question

 (a) On a map, the height of Hillibar Station is 1047m and the height of Sular Junction is 297m.
(i) Calculate the difference in these heights.
(ii) The temperature falls by 1°C for every 100m increase in height.
One day the temperature in Sular Junction is 19°C.
Work out the temperature at Hillibar Station.
(iii) Write 297 correct to the nearest ten.
(iv) Write 1047 correct to the nearest hundred.
(b) (i) Kim arrives at Hillibar Station at 1235.
The taxi to her hotel takes 27 minutes.
Work out the time Kim arrives at her hotel.
(ii) Henry takes 17 minutes to walk from his home to Sular Junction.
He must arrive there by 10 43.
Work out the latest time he can leave home.
(c) Here is part of a train timetable.
Each journey from Sular Junction to Hillibar Station takes the same time.

(i) Complete the timetable.
(ii) The distance between Sular Junction and Hillibar Station is 64km.
Calculate the average speed, in kilometres per hour, of a train between these two stations.
(iii) Joel arrives at Sular Junction at 1148.
At what time is the next train to Hillibar Station due to depart?

Answer/Explanation

Answer:

(a) (i) 750
(ii) 11, 11.5 or 12
(iii) 300
(iv) 1000

(b) (i) 13 02
(ii) 10 26

(c) (i) 16  24
(ii) 40 cao
(iii) 12  32

Question

(a) The table shows the temperature at noon each day for one week in a city.

MondayTuesdayWednesdayThursdayFridaySaturdaySunday
5°C2 °C−3°C−1°C0 °C1°C−2 °C

(i) Which day had the lowest noon temperature?
(ii) Find the difference between the noon temperatures on Tuesday and Wednesday.
……………………………………….°C
(iii) Write these seven temperatures in order, starting with the lowest.
(iv) On Sunday the noon temperature was −2°C.
The next day the noon temperature fell by 4°C.
Find the noon temperature on the next day.
(b) The number of houses in the city is 1935 364.
Write this number correct to the nearest million.
(c) The height, h metres, of a tower in the city is 120m, correct to the nearest 10m.
Complete this statement about the value of h.
……………….. G h < ………………..
(d) The diagram shows the cross section of a circular tunnel in the city.

Calculate the shaded area.

Answer/Explanation

Answer:

(a) (i) Wednesday
(ii) 5
(iii) -3   -2   -1   0   1   2   5
(iv) -6

(b) 2 million or 2 000000

(c) 115     125

(d) 28.3 or 28.27 to 28.28

Question

 The scale drawing shows the positions of Bogota (B) and Quito (Q).
The scale is 1 centimetre represents 150 kilometres.

(a) (i) Measure the length of the line BQ.
…………………………………… cm

(ii) Work out the actual distance from Bogota to Quito.
…………………………………… km
(iii) Measure the bearing of Quito from Bogota.
(b) A plane leaves Quito and flies straight to Manaus.
Manaus is 2100 km on a bearing of 100° from Quito.
On the scale drawing, mark the position of Manaus (M).
(c) The plane flies the 2100km from Quito to Manaus at an average speed of 550km/h.
Calculate the time taken for this flight
(i) in hours, correct to 3 significant figures,
…………… h
(ii) in hours and minutes, correct to the nearest minute.
…………………… h …………………… min

Answer/Explanation

Answer:

(a) (i) 4.4
(ii) 660
(iii) 220

(b) 14 [cm] from Q
100° from Q

(c) (i) 3.82 cao
(ii) 3[h] 49[min]

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