# Add a percentage is a Multiplication

Add a percentage, say 5% is not making an addition. It is a multiplication by (1+5/100). You may also multiply by 5, divide by 100, and then add the result to the original amount.

The Blog of Mathedu Academy

A content for the curious of the mathematics in the real world… and beyond, including video tutorials.

We learned in the previous post to add a percentage with a multiplication, let’s now learn the different manipulations of percentage.

Well, the day length is exactly the time by which the earth makes a turnaround on itself. And the year is exactly the time by which the earth makes a complete revolution around the sun.

Thus, the number of days of the year must be the ratio of the year length on the day length say, in seconds.

The problem is that there is no reason for that ratio to be an integer…

Thus, the number of days of the year must be the ratio of the year length on the day length say, in seconds.

The problem is that there is no reason for that ratio to be an integer…

Our scientific calculators deal sometimes with numbers with a \( E \) inside: this is the so called Exponential, or Scientific Notation.

But what does that mean, and how to read such numbers?

But what does that mean, and how to read such numbers?