What is Making an Amount Using Coins?

S1-SA4-0502

Grade Level:

Class 2

Finance, Economics, Computing, AI

Definition

What is it?

Making an amount using coins means finding different ways to combine coins of various values (like 1 rupee, 2 rupees, 5 rupees, 10 rupees) to reach a specific total amount. It's like solving a puzzle to get the exact money needed.

Simple Example

Quick Example

Imagine you want to buy a small packet of biscuits that costs ₹7. You need to pick coins from your pocket to make exactly ₹7. You could use one ₹5 coin and two ₹1 coins, or maybe three ₹2 coins and one ₹1 coin.

Worked Example

Step-by-Step

Let's say you need to pay ₹12 for an ice cream. You have coins of ₹1, ₹2, ₹5, and ₹10.

Step 1: Start with the largest coin that is less than or equal to the amount. We can use one ₹10 coin.
---Step 2: After using ₹10, the remaining amount is ₹12 - ₹10 = ₹2.
---Step 3: Now, we need to make ₹2. We can use one ₹2 coin.
---Step 4: So, to make ₹12, we used one ₹10 coin and one ₹2 coin.
---Answer: One ₹10 coin and one ₹2 coin make ₹12.

Why It Matters

Understanding how to make amounts with coins is fundamental to managing money, a key skill in Finance and Economics. It helps in daily transactions and even in understanding how digital payments (like UPI) break down costs. This skill is useful for cashiers, shopkeepers, and anyone handling money.

Common Mistakes

MISTAKE: Only using one type of coin to make an amount, even when other combinations are easier or required. | CORRECTION: Always consider using a mix of different coin values to find the most efficient way or if a specific coin is unavailable.

MISTAKE: Adding up coin values incorrectly, leading to a wrong total. | CORRECTION: Double-check your addition carefully. Count each coin's value one by one and sum them up to ensure accuracy.

MISTAKE: Forgetting to use the largest possible coin first, making the process longer. | CORRECTION: Always try to use the largest coin value possible that is less than or equal to the remaining amount. This often simplifies the problem.

Practice Questions

Try It Yourself

QUESTION: How can you make ₹8 using ₹1 and ₹2 coins? | ANSWER: Four ₹2 coins OR eight ₹1 coins OR three ₹2 coins and two ₹1 coins.

QUESTION: You need to pay ₹17 for a samosa and chai. You have ₹1, ₹2, ₹5, and ₹10 coins. How can you make exactly ₹17 using the fewest coins possible? | ANSWER: One ₹10 coin, one ₹5 coin, and one ₹2 coin.

QUESTION: Your friend needs ₹23 for a bus ticket. You have two ₹10 coins, three ₹5 coins, and four ₹2 coins. What combination of your coins can you give your friend to make exactly ₹23? | ANSWER: Two ₹10 coins and one ₹2 coin and one ₹1 coin (if ₹1 coins were available). Given the coins, two ₹10 coins and one ₹2 coin and one more ₹1 coin is needed. Or, one ₹10 coin, two ₹5 coins, and one ₹2 coin, and one ₹1 coin is needed. Since ₹1 is not available, then one ₹10 coin, two ₹5 coins, and two ₹2 coins. Or, one ₹10 coin, one ₹5 coin, and four ₹2 coins.

MCQ

Quick Quiz

Which combination of coins makes exactly ₹13?

One ₹10 coin, one ₹2 coin, one ₹1 coin

Two ₹5 coins, two ₹2 coins

One ₹10 coin, three ₹1 coins

All of the above

The Correct Answer Is:

Option A (10+2+1=13), Option B (5+5+2+1=13), and Option C (10+1+1+1=13) all correctly make ₹13. Therefore, 'All of the above' is the correct answer.

Real World Connection

In the Real World

Every time you buy something from a small shop or a 'thela' (street vendor) in India, you are making an amount using coins. For instance, if a vendor says your total is ₹38, you might give them two ₹10 coins, three ₹5 coins, and one ₹2 coin, or any other mix that totals ₹38.

Key Vocabulary

Key Terms

COIN: A flat, round piece of metal used as money | AMOUNT: The total value or sum of money | VALUE: How much a coin or currency is worth | COMBINATION: Different ways to put things together to form a total

What's Next

What to Learn Next

Once you master making amounts with coins, you can move on to 'Giving Change'. This builds on your current skill by adding subtraction, as you'll learn to calculate how much money to return after a purchase. Keep practicing, it's a super useful skill!