3rd Class Mathematics Money Money

Money

Introduction

Money is the medium of exchange. We pay the money equivalent to the cost of things we buy. It is available in two forms, coins and notes. In ancient word coins were made up of gold and silver.

Conversion of Money

Conversion of Rupees into Paise

Hundredth part of one rupee is one paise. Therefore, rupees and paise are converted into each other by the factor of 100.

Following are the steps used in the conversion of rupees into paise.

Step 1: To convert rupees into paise, multiply the number of rupees by 100.

Step 2: Resulting product is obtained in paise.

i. e. Rupees \[5\text{ }=\text{ }5\text{ }\times \text{ }100\text{ }paise=\text{ }500\text{ }paise.\]

Conversion of Paise into Rupees

Following are the steps used in the conversion of paise into rupees.

Step 1: Divide paise by 100.

Step 2: Put a dot mark after two digits from right in paise,

Step 3: The resulting product is obtained in rupees.

•           Example

How much A will get if B gives 34 of 5 rupees coins?

            (a) 16000 paise                                                   (b) 17000 paise  

            (c) 10000 paise                                                   (d) All the above

            (e) None of these

Ans.     (b)

            Explanation: A will get ` 34 \[\times \] 5 = ` 170 = 17000 paise.

Operations on Money

Addition of Money

Following are the steps used in the addition of money,

Step 1: Arrange the money vertically, rupees under rupees column and paise under paise column.

Step 2: Add the money from right or paise.

Step 3: If carry is generated then add the carry to the next addition.

Step 4: The resulting value of money is their addition.

•           Example

Add ` 18 and 20 paise and ` 20 and 80 paise.

Subtraction of Money

Following are the steps used in the subtraction of money.

Step 1: Arrange the money vertically, rupees under rupees column and paise under paise column.

Step 2: Subtract the money starting from right or paise.

Step 3: Take borrow if required.

•           Example

Subtract ` 34.50 from ` 45.10

•          Example

Money paid by Peter to a shopkeeper is ` 45 for the cost of rice and ` 75.50 for the cost of oil. How much money is paid by Peter?

            (a) ` 100.50                                                       (b) ` 121.45     

            (c) ` 120.50                                                       (d) All the above

            (e) None of these

Ans.     (c)

            Explanation: Money paid by peter = ` 45 + ` 75.00 = ` 120.50

Unitary Method

Unitary method is self-indicating, In other words, this is the method informing the cost of unit article, if the cost of more than one article is given. This method is widely used for the simplification of word based problems.

Use of Unitary Method for Solving Money Based Problems

The value of required number of articles is obtained by finding the value of unit article.

•            Example

What is the cost of 1 article if the cost of 10 articles is ` 2500?

            (a) ` 250                                                           (b) ` 350

            (c) ` 300                                                            (d) ` 150

            (e) None of these

Ans.     (a)

            Explanation: Cost of 1 article \[=\,\,\frac{total\cos t}{Number\,of\,articles}\,\,\,\,\,\,\,\,\]

Ø  Example

Find the cost of one fourth of 56 apples if the cost of an apple is ` 7     

            (a) ` 88                                                            (b) ` 98

            (c) ` 78                                                             (d) ` 68

            (e) None of these

Ans.     (b)

Explanation: Number of apples  \[=\,\,\frac{56}{4}\,\,=\,14\]

Total cost = ` (14 \[\times \] 7) = ` 98.