Money Class 4 Notes Maths

Different countries use different currencies. Indian currency is known as rupees.

Indian Currency: Rupees and Paise

Conversion of Rupees into Paise and Paise into Rupees

Example:

₹ 1 = 100 paise,  Then
₹ 2 = 2 × 100 paise = 200 paise
₹ 3 = 3 × 100 paise = 300 paise,
₹ 4 = 4 × 100 paise = 400 paise

Below are some of the rules for the conversion of rupees into paise and vice versa.

Rule 1: 

To change an amount in ‘rupees’ and ‘paise’ into paise we multiply the number of rupees by 100 and add it to the number of paise.

Example 1: Convert 35 rupees 25 paise into paise.

Sol: 35 rupees 25 paise = (35 × 100) paise + 25 paise
= 3500 paise + 25 paise
= 3525 paise

Rule 2: 

To convert an amount given in rupees into paise, we remove the symbol of ₹ and the point and write paise.

Example 2: Convert the following amounts into paise.
(a) ₹ 41.25
(b) ₹ 106.50
(c) ₹ 0.25

Sol: (a) ₹ 41.25 = 4125 paise
(b) ₹ 106.50 = 10650 paise
(c) ₹ 0.25 = 25 paise

Rule 3: 

To convert an amount given in paise into rupees, we put a point after two digits from the right of the given number showing paise. The number on the left of the point gives the number of rupees and that on the right gives paise.
Conversion of rupees into paise and vice versa

Example 3: Convert the following into rupees.
(a) 4535 p
(b) 9p
(c) 505 p

Sol: (a) 4535 p = ₹ 45.35
(b) 9p = ₹ 0.09
(c) 505 p = ₹ 5.05

Addition of Money

Some practical situations involve addition of money. To find the total amount we write one amount under the other such that the point is exactly under the point and add as ordinary numbers.

Example 4: Add ₹ 217.31 and ₹ 335.46.

Thus, ₹ 217.31 +  ₹335.46 = ₹552.77

Subtraction of Money

Some practical situations involve the subtraction of money. To find the difference we write one amount under the other such that the point is exactly under the point and subtract as ordinary numbers.

Example 5: Subtract ₹127.56 from ₹579.86.

Thus, ₹579.86 – ₹127.56 = ₹452.30.

Multiplication of Money by a Number

Some practical situations involve the multiplication of a sum of money expressed by a number using a point. To find the product we multiply in the usual way and put the point two places from the right.

Example 6: Find ₹312.97 × 3.

Sol: We have

31297 × 3 = 93891
₹312.97 × 3 = ₹938.91
Thus ₹312.97 × 3 = ₹938.91.

Division of  Money by a Number

Divide the amount given by the given whole number, taking the amount as an ordinary number. Put a decimal point after 2 digits from the right in the quotient.

Example 7: Divide ₹22750 by 14.

Thus, the quotient is ₹1625.

Example 8: Divide ₹115.15 by 7

First divide 11515 by 7
₹11515 ÷ 7 = 1645
Hence, ₹115.15 ÷ 7 = ₹16.45

Estimating Money

At times, we do not need to know the exact amount of money, but we need to get an idea of the cost. To find it, we round off the amount to the nearest rupee. This is called the estimation of money.

Example 13: Round off the following to the nearest rupee:
(a) ₹523.96
(b) ₹684.35

Sol: (a) ₹523.96 = ₹524 (Rounding 96 p to the nearest hundred, we get 100 p or ₹1.)
₹523 + ₹1 = ₹524

(b) ₹684.35 = ₹684 (Rounding 35 p to the nearest hundred, we get 0 p. This can be taken as ₹ 0.)
₹684 + ₹0 = ₹684

Estimating Sum and Difference

Sometimes, it's helpful to round off amounts to the nearest rupee to make calculations easier. Here's how you do it:

Steps to Round Off Amounts

1. Identify the Amount:

   • Look at the amount you need to round off. For example, let's take ₹112.86.

2. Check the Paise (Decimal Part):

   • If the paise (the part after the decimal) is 50 or more, round up to the next rupee.
   • If the paise is less than 50, round down to the nearest lower rupee.

Example:

1. Amount: ₹112.86

   • The decimal part is .86 (which is more than 50).
   • Round up to the next rupee: ₹112.86 becomes ₹113.

2. Amount: ₹39.63

   • The decimal part is .63 (which is more than 50).
   • Round up to the next rupee: ₹39.63 becomes ₹40.

Adding Rounded Amounts

After rounding off, you can add the amounts easily.

Example:

• Original amounts: ₹112.86 and ₹39.63.
• Rounded amounts: ₹113 and ₹40.
• Add the rounded amounts: ₹113 + ₹40 = ₹153.