5th Class Mental Ability Estimation Estimation

Estimation

Objectives

·                     Students will be able to generate a range of possible outcomes.

·                     They will be able to judge the size, amount and cost of given things.

Introduction

Estimation is a rough calculation of the value, number, quantity, or extent of something.

Example 1:

Mandeep walks the following distance each day of the week. Estimate the total distance that he walks.

 (a) 25                          (b) 27                          

(c) 30                           (d) 35

Ans. (b)

Explanation: The total distance = 4.5 + 3.5 + 1.5 + 2 + 4 + 5 + 6.5 = 27 km.

Example 2:

Estimate 2,342 + 738. Round to the hundred place.

(a) 3180                       (b) 3200          

(c) 3100                       (d) 3191

Ans. (c)

Explanation: Round each number to the nearest whole numbers

Example 3:

How many-250 ml cartons of milk would it take to fill the 11 carton?

(a) 2                             (b) 3                            

(c) 4                             (d) 5

Ans. (c)

Explanation:

Example 4:

Mr. Gautam had 396 crayons left over at the end of the year. He's putting them in bags to send home with the kids. He has 20 students in his class. About how many crayons will each student get?

(a) 20                           (b) 30                          

(c) 40                           (d) 25

Ans. (a)

Explanation: 396 is close to 400. 20 is already a friendly number.

\[400\div 20=20,\] so each student will get about 20 crayons.

Example 5:

Ben had 2 boxes of blocks

Each box had 50 blocks

He built a tower with \[\frac{1}{5}\] of the blocks out of each of the boxes.

How many blocks did Ben use to build the tower?

(a) 50                           (b) 40                          

(c) 30                           (d) 20

Ans. (d)

Explanation: Each box had = 50 blocks

2 boxes had \[=\text{ }50\times 2=100\]blocks

Ben used \[\frac{1}{5}\] of blocks \[=\text{ }100\text{ }\times \frac{1}{5}=20\] blocks.