Money and Decimals
Money and decimals are closely connected. In India, money is written using the rupee (₹) and paise system. Since 100 paise = 1 rupee, paise are written as a decimal part of a rupee. For example, ₹5.50 means 5 rupees and 50 paise.
Understanding how to convert between rupees and paise, add and subtract money amounts, and solve shopping problems using decimals is an essential everyday skill.
What is Money and Decimals - Class 4 Maths (Decimals)?
Money in decimal form:
100 paise = ₹1
1 paise = ₹0.01
₹a and b paise = ₹a.b (if b < 10, write as ₹a.0b)
Conversion rules:
- Paise to Rupees: Divide by 100 (or put a decimal point two places from the right).
- Rupees to Paise: Multiply by 100 (or remove the decimal point and write as paise).
Examples: 350 paise = ₹3.50, ₹7.05 = 705 paise, 60 paise = ₹0.60
Solved Examples
Example 1: Example 1: Converting Paise to Rupees
Problem: Convert 475 paise to rupees.
Solution:
Step 1: Divide by 100: 475 ÷ 100 = 4.75
Answer: 475 paise = ₹4.75
Example 2: Example 2: Converting Rupees to Paise
Problem: Convert ₹8.30 to paise.
Solution:
Step 1: Multiply by 100: 8.30 x 100 = 830
Answer: ₹8.30 = 830 paise
Example 3: Example 3: Writing Money in Decimal Form
Problem: Write 12 rupees and 5 paise in decimal form.
Solution:
Step 1: 5 paise is less than 10, so write it as 05.
Answer: ₹12.05
Example 4: Example 4: Adding Money
Problem: Ria bought a book for ₹65.50 and a pen for ₹18.75. How much did she spend in total?
Solution:
₹65.50
+ ₹18.75
--------
₹84.25
Answer: Ria spent ₹84.25.
Example 5: Example 5: Subtracting Money
Problem: Rahul had ₹200. He bought a cricket ball for ₹145.50. How much money is left?
Solution:
₹200.00
− ₹145.50
---------
₹54.50
Answer: Rahul has ₹54.50 left.
Example 6: Example 6: Comparing Money Amounts
Problem: Which is more: ₹45.80 or ₹45.08?
Solution:
Step 1: Rupees part: 45 = 45 (same).
Step 2: Compare paise: 80 paise > 08 paise.
Answer: ₹45.80 > ₹45.08
Example 7: Example 7: Word Problem — Shopping List
Problem: Aditi buys: Tiffin box ₹125.50, Water bottle ₹89.75, Pencil box ₹55.25. How much is the total?
Solution:
₹125.50
₹89.75
+ ₹55.25
--------
₹270.50
Answer: Total = ₹270.50
Example 8: Example 8: Finding Change
Problem: Meera gave ₹500 for a dress costing ₹378.25. How much change will she get?
Solution:
₹500.00
− ₹378.25
---------
₹121.75
Answer: Meera gets ₹121.75 change.
Example 9: Example 9: Multiplication with Money
Problem: One chocolate costs ₹12.50. What is the cost of 4 chocolates?
Solution:
Step 1: 12.50 x 4 = 50.00
Answer: 4 chocolates cost ₹50.00.
Example 10: Example 10: Converting and Adding
Problem: Dev has ₹23.50 and 175 paise. How much money does he have in total?
Solution:
Step 1: Convert 175 paise to rupees: 175 ÷ 100 = ₹1.75
Step 2: Add: ₹23.50 + ₹1.75 = ₹25.25
Answer: Dev has ₹25.25 in total.
Key Points to Remember
- 100 paise = ₹1. Paise are the decimal part of rupees.
- To convert paise to rupees, divide by 100.
- To convert rupees to paise, multiply by 100.
- When writing money, always use two decimal places (₹5.05, not ₹5.5 for 5 rupees 5 paise).
- Adding and subtracting money works exactly like decimal addition and subtraction.
- Always align the decimal point when adding or subtracting money amounts.
Practice Problems
- Convert 825 paise to rupees.
- Convert ₹6.05 to paise.
- Aman bought a toy for ₹85.50 and a ball for ₹42.25. How much did he spend?
- Priya had ₹300. She spent ₹187.75. How much is left?
- Write 9 rupees and 7 paise in decimal form.
- Which is greater: ₹56.09 or ₹56.90?
- 5 erasers cost ₹7.50 each. What is the total cost?
Frequently Asked Questions
Q1. How many paise make 1 rupee?
100 paise make 1 rupee. So ₹1 = 100 paise, ₹2.50 = 250 paise, and so on.
Q2. How do you write 8 rupees and 5 paise in decimal form?
Write it as ₹8.05. Since 5 paise is a single digit, add a 0 before it in the decimal part. Never write ₹8.5 for 8 rupees 5 paise (that would mean 8 rupees 50 paise).
Q3. What is the difference between ₹3.5 and ₹3.50?
Mathematically, ₹3.5 and ₹3.50 are the same value (3 rupees 50 paise). However, when writing money, always use two decimal places (₹3.50) for clarity.
Q4. How do you add rupees and paise together?
Convert everything to the same unit (either all rupees with decimals, or all paise), then add. Aligning decimal points is the easiest method.
Q5. How do you find change after a purchase?
Subtract the cost from the amount paid. Write both amounts with two decimal places and subtract. For example, ₹50.00 − ₹32.75 = ₹17.25.
Q6. Can you multiply money by a whole number?
Yes. Multiply as with normal decimals. For example, ₹4.50 x 3 = ₹13.50. This is useful for finding the cost of multiple items.
Q7. Why is money written with two decimal places?
Because there are 100 paise in a rupee, and 100 requires two decimal places. This ensures that 5 paise is written as .05 and 50 paise as .50, avoiding confusion.
Q8. Is money and decimals part of NCERT Class 4?
Yes, understanding money as a decimal (rupees and paise) is part of the CBSE/NCERT Class 4 curriculum, connecting the decimals chapter with real-life applications.
