Estimation Worksheets 2
Source: New Syllabus Mathematics Workbook 1: 7th Edition
10. Estimate the area of a circle of radius 6.27 cm.
11. A race car driver has 28 cars. Each car has four tires. He has to replace all the tires on
the cars. He has 22 tires right now. Estimate the total number of tires he needs to buy.
12. On Monday, Cody bought 414141 cherries. On Tuesday, Cody ate 191919 cherries. Now,
she wants to divide the remaining cherries into bags of 444 cherries each.
Estimate how many bags of 444 cherries Cody can make.
13. A shirt costs 27 800 Korean Won (KRW). The conversion rate is $1= KRW 876. Without
using a calculator, estimate the price of the shirt in $.
Source: New Syllabus Mathematics Workbook 1: 7th Edition
14. Lixin makes the following orders from a supermarket.
Item
Apples
Bananas
Potatoes
Tomatoes
Quantity
18
1.2 kg
2 kg
2.2 kg
Cost
3 for 99 cents
$1.50 per kg
81 cents per kg
$3.40 per kg
Show how you estimate the total amount of money she has to pay, giving your answer correct to
the nearest dollar.
15. Three budget airlines are offering special discount for post new Lunar new year flight to
Bangkok for a 3 days 2 nights stay.
Airline A offers $88.020 with a discount of 20%.
Airline B offers $93, which include the cost of one night accommodation, $35
Airline C offers $75 with a discount of 10%.
Write down a calculation you could mentally to help you decide which airline’s offer is the best.
16. Without using a calculator, decide which of the options is better value of money is.
Option A NPPC Supermarket
1 bottle of 700 ml X shampoo
$4.00
Option B Shop everyday Supermarket
2 bottles of X shampoo 700 ml + 700 ml
$8.90
Option C Hot storage Supermarket
2 bottles of X shampoo 700 ml + 250 ml
$9.90
Source: New Syllabus Mathematics Workbook 1: 7th Edition