Understand Concept of Money | Mental Maths - Class 1 PDF Download

Expressing Money in Words and Figures

We can express money both in words and figures.
Suppose, Aman has thirty-eight rupees and a fifty paise. In words, we express this amount as rupees thirty-eight and fifty paise or thirty-eight rupees and fifty paise.
To express this amount in figures, we make use of symbols.
We use the symbol ₹ for rupee. Thus, 10 rupees is written as ₹ 10 and one rupee is written as ₹ 1.
Using symbols, the amount of thirty-eight rupees and fifty paise will be written as ₹ 38.50. The dot (.) is used for the word ‘and’. As a convention, we do not write p.

One rupee can be written as ₹ 1.00 or ₹ 1.
Now, let us read the following amounts.
₹ 3.09  is read as three rupees and nine paise.
₹ 73.50  is read as seventy-three rupees and fifty paise.
Amounts less than one rupee may be shown either with the symbol ‘p’ of paise or with the symbol of rupees and the dot.
Examples: We write
(a) Eight paise as 8 p or ₹ 0.08
(b) Fifty paise as 50 p or ₹ 0.50
(c) Seventy-five paise as 75 p or ₹ 0.75

Conversion of Rupees into Paise

We follow the following rules to convert rupees into paise.

Rule 1: To convert rupees into paise, multiply the amount of rupees by 100.

Examples:
Since, 1 rupee = 100 paise
₹ 9 = 9 × 100 p = 900 p
₹ 48 = 48 × 100 p = 4800 p

Rule 2: To convert rupees and paise into paise, multiply the amount of rupees by 100 and add it to the number of paise

Examples: 
₹ 15.90 = 15 rupees 90 paise
= 15 × 100 p + 90 p
= 1500 p + 90 p = 1590 p 
₹ 65.05 = 65 rupees 5 paise
= 65 × 100 p + 5 p
= 6500 p + 5 p = 6505 p

Edurev Tips: Just remove the dot and you will get the answer in paise.

Conversion of Paise into Rupees

Rule: To convert paise into rupees and paise, we separate the ones and tens digits from the given number of paise. The number formed by ones and tens digits gives us the paise and remaining number gives us the rupees.

Examples:
6825 paise = ₹ 68.25
5550 paise = ₹ 55.50
915 paise = ₹ 9.15

Addition of Money

Method:
Step 1: Arrange the amounts to be added in the columns of rupees and paise.
Step 2: Add the paise.
Step 3: Now, add the rupees.

Example 1: Add ₹ 42.15 and ₹ 85.74.
Sol: 

Alternate Method:
Thus, ₹ 42.15 + ₹ 85.74 = ₹ 127.89.

Example 2: Add ₹ 157.75 and ₹ 64.87.
Sol: 

Thus, ₹ 157.75 + ₹ 64.87 = ₹ 222.62.

Edurev Tips: It is clear from the above example that while adding money, we can carry from ones to tens and from tens to hundreds, etc., in the same way as we did in the case of numbers.

Example 3: Saurav had ₹ 698.27 with him in his bank and his father gave him thirty-eight rupees and five paise. How much did Saurav have then?
Sol:

Thus, Saurav had ₹ 736.32 with him.

Subtraction of Money

Method:
Step 1: Arrange the bigger amounts above smaller amount in the columns of rupees and paise.
Step 2: Subtract the paise.
Step 3: Subtract the rupees.

Example 1: Subtract ₹ 43.15 from ₹ 88.78.
Sol: 

Thus, ₹ 88.78 – ₹ 43.15 = ₹ 45.63
Alternate Method:

Example 2: Subtract ₹ 49.17 from ₹ 92.06.
Sol: 

Thus, ₹ 92.06 – ₹ 49.17 = ₹ 42.89.

Example 3: Amina spends ₹ 110.65 on gifts for her mother. Her sister spends 240 rupees and 7 paise. How much more does she spend than Amina?
Sol:

Thus, Amina’s sister spends ₹ 129.42 more than Amina on their mother’s gifts.

Edurev Tips: In the p column, always write paise in two figures, i.e., 7 paise should be written as 07 p.

Multiplication of Money

Method:
Step 1: Multiply the rupees and paise, as you do in case of ordinary numbers.
Step 2: Put the point (.) after the second digit from the right.

Example 1: One litre of milk costs ₹ 65.75. How much would 8 litres of milk cost?
Sol: 
Cost of 1 litre of milk = ` 65.75
Cost of 8 litres of milk = ₹ 65.75 × 8 = ₹ 526.00.