Code / Python for Beginners / Unit 2: Maths and decisions

f-strings and maths f-string और गणित

Lesson 4 of 14 · about 15 minutes · Neat messages with f-strings; //, % and round().

⚡ 0 XP

Step 1 of 3

f-strings: fill in the blanks

Gluing text with + gets messy, and you must remember str() for numbers. An f-string is easier: put f before the quotes and write variables inside { }.

f"Hi {name}, your plan is ₹{price}"

You can even do maths inside the braces: f"A year costs ₹{price * 12}". Python works out the value and drops it into the text. No str() needed.

Example

name = "Meera"
price = 239
print(f"Hi {name}, your plan is ₹{price}")
print(f"A year costs ₹{price * 12}")

🎯 Challenge: Mobile recharge message +15 XP

The program reads a name and a plan price (a number). Using f-strings, print two lines. For Asha and 299 they must be:

Hi Asha, your ₹299 plan is active.
12 recharges cost ₹3588 in a year.

Work out 12 × price inside the braces.

Try twice to unlock the solution (0/2)

main.pyCtrl ⏎

⌨ Inputs one answer per line, used by input()

Output

What your program prints appears here.

Checklist

Press Run to check your code.

Greets with the plan price
Shows the yearly cost
Works for Ravi with ₹199
Uses an f-string

Lesson notes (text version)

1. f-strings: fill in the blanks

Gluing text with + gets messy, and you must remember str() for numbers. An f-string is easier: put f before the quotes and write variables inside { }.

f"Hi {name}, your plan is ₹{price}"

You can even do maths inside the braces: f"A year costs ₹{price * 12}". Python works out the value and drops it into the text. No str() needed.

                name = "Meera"
price = 239
print(f"Hi {name}, your plan is ₹{price}")
print(f"A year costs ₹{price * 12}")

Challenge: Mobile recharge message

The program reads a name and a plan price (a number). Using f-strings, print two lines. For Asha and 299 they must be:

Hi Asha, your ₹299 plan is active.
12 recharges cost ₹3588 in a year.

Work out 12 × price inside the braces.

2. // and %: boxes and leftovers

Python has two maths operators that are perfect for packing things:

// is floor division: how many whole times. 100 // 12 is 8
% is remainder (modulo): what is left over. 100 % 12 is 4

So 100 laddoos make 8 full boxes of 12, with 4 laddoos left over. (Plain / would give 8.333…, which is not much use when packing boxes.)

Other operators: + - *, and ** for power: 2 ** 3 is 8.

                print(100 / 12)
print(100 // 12)
print(100 % 12)
print(2 ** 10)

Challenge: Diwali laddoo boxes

Each Diwali box holds 12 laddoos. The program reads how many laddoos were made. Store the number of full boxes in boxes (use //) and the leftovers in left (use %). Print Full boxes: 8 and Left over: 4 for 100 laddoos.

3. round() for tidy decimals

Division with / often gives long decimals: 157 / 20 is 7.85, but 200 / 35 is 5.714285714285714. Nobody wants that on a scoreboard!

round(x, 2) rounds x to 2 decimal places: round(5.714285, 2) is 5.71. Without the second number, round() gives a whole number: round(5.7) is 6.

                print(200 / 35)
print(round(200 / 35, 2))
print(round(5.7))

Challenge: Cricket run rate

Run rate = runs ÷ overs. The program reads runs and overs (whole numbers). Store the run rate rounded to 2 decimals in rate, and print Run rate: 7.85 for 157 runs in 20 overs. (For 200 runs in 35 overs it should print Run rate: 5.71.)