RedCrab Math Tutorial

# Calculation of Interest

The interest calculation is an extension of the percentage calculation. Interest is a percent value of one underlying or principal.

Base of the percentage calculation is the formula:

Z = Interest

K = Principal

P = Interest rate

The formula can be changed for the value you are looking for

Interest rate:

Interest:

Principal:

## Calculate interest income

This example calculates the interest earned on investing 3000\$ for one year at a fixed rate of 3%.
Given is the interest rate P = 3 and the capital = 3000.
We are looking for the interest income Z.
The interest income is calculated according to the formula:\$

## Calculate interest rate

This example calculates the interest rate, which is required to receive \$ 150 interest in one year, from a capital of \$ 3,000
The capital K = 300 and the interest income Z = 150 are known.
We are looking for the interest rate P.
Calculated according to the formula:

## Calculate starting capital

What amount must be invested in order to receive an interest income of 200 \$ at a rate of 5%? This question should be solved in this task.
The interest rate of P = 5% and the interest income Z = 200 \$ are known
We are looking for starting capital K.

It is calculated according to the formula: \$

## Calculate interest income daily

For example, suppose you want to invest \$ 5,000 for 2 months at an annual interest rate of 5%. For this, the interest must be calculated on a daily basis. The formula for calculating the interest income is extended accordingly by the number of days = t. For each month, 30 days, so 360 days for 1 year are assume.

The capital K = 5000, the interest rate P = 5 and the number of days t = 60 are known
We are looking for interest income Z.

This is calculated: \$

## Arithmetic

Integer and Real Numbers
Complex Numbers
Sets
Roots and Power
Percentage Calculation
Interest Calculation
Absolute Value of a Number
Euclidean division
Modulo - Remainder of a division
Vectors
Matrices