IGCSE Mathematics Paper1: Specimen Questions with Answers 32  32 of 175
Question number: 32
Describe in Detail
The table above gives the areas of forests of different countries, correct to 4 significant figures.
Forests of Countries  Area ( ) 
Russia 

Brazil 

Canada 

United States 

(a) List the Forests of Countries in order of area, smallest to largest.
________ < Canada < ________ < ________.
(b) Use a whole number to complete the statement in the answer space.
The area of forests of Russia is approximately ________ times the area of forests of Canada.
Explanation
Here, correct the area of the countries to 4 significant figures:
 Area of forest of Russia will be: 7,763,000 because after fourth significant digit 2 there is 6 which is greater than 5, so 2 will be rounded and be 3.
 Area of forest of Brazil will be: 4,777,000 because after fourth significant digit 6 there is 9 which is greater than 5, so 6 will be rounded and be 7.
 Area of forest of Canada will be: 3,101,000 because after fourth significant digit 1 there is 3 which is less than 5, so 1 will remain same.
 Area of forest of United States will be: 3,031,000 because after fourth significant digit 0 there is 8 which is greater than 5, so 0 will be rounded and be 1.
(a) Here, list of countries as per smallest to largest areas as below:
United States < Canada < Brazil < Russia
Because
(b) Here, area of forests of Russia by using whole number is:
Area of forests of Canada by using whole number is:
So, the area of forests of Russia is approximately 2.5 times the area of forests of Canada.
( Calculation: )