# Calculate the interest

Hello, I have difficulty understanding part of the code of the following question:

You want to invest capital πΆ0 for n years at an annual interest rate of i%.
The relation is given by: πΆ = πΆ0*(1 + π)^π.
Write a program giving you the amount earned, the interest (πΌ = πΆ β πΆ0) of your
investment, as well as the equivalent monthly interest rate ππ under the database
provided. ππ = (1 + π)^(1/12) β 1.

The following would be the answer:

from math import *

C0 = float(input(βStarting capital: β))
i = float(input("Annual interest rate: "))
i = i / 100
u = 1 + i
n = int(input("Number of years: "))
print(ββ)

C = C0 * (un)
I = C - C0
im = u
(1/12) - 1

C = int(100 * C)/100
I = int(100 * I)/100
im = int(10000 * im)/100

print(βCapital afterβ, n, βyears:β, C, ββ¬β)
print('Interest: ', I, ββ¬β)
print("Monthly interest rate: ", im, β%β)

The code I donβt understand is the following:

I do not understand why this was written, what it means and how it affects the code:

C = int(100 * C)/100
I = int(100 * I)/100
im = int(10000 * im)/100

Many thanks for who can help me out!

If youβre posting code to the forums please see: How do I format code in my posts? which lets you keep the original text its indentation and formats it nicely. Do you have a link to the lesson?

Seems like a coarse route to try and round values (trimming non significant figures). If you want to see the different print once before those steps and then print again afterwards.

the code is in a pdf document.