# Natural Science and Mathematics

This portal is all about natural science and math. You can check out the sub portals mathematics and statistics, physics, chemistry, biology, geography as well as astronomy and space:

## Computer Science, Geography and Human Sciences

For topics on computer science, see the portal Programming and Computer Science, for humanities topics refer to the portal Art, Culture, People, Politics and Society

Other scientific topics such as geography, weather, environment and ecology, can be found in the portal Nature, Environment, Animals and Plants.

## New Topics

The first 100,000 Digits of Pi
I have often been asked the question, how many decimal places Pi actually has. The answer is: Pi is an irrational number and...
How many decimal places does Pi have?
When entering the number Pi in my pocket calculator, I exactly get 9 decimal places displayed (3,141592654). Recently, my teacher...
Convert Fractions into Percentages
I have to convert some fractions to their corresponding percentages for a piece of homework. The task is for example that...
What is the number Pi written out completely?
Recently, we have started using the number Pi in our mathematics lessons, for example to be able to calculate the circumference...
Determine Median for even Number of Values
Usually, you are determining the median by sorting the values according to their size and the median is just the middle value...
Calculate Correlation or Covariance for non-equal Sample Sizes
For my studies in university, I have to calculate correlations and covariances for several series of measurements. Up to now, I...

Square: Writing out pi completely with all of its decimal places is impossible according to the current state of science. The reason is that the...
Square: Pi is an irrational number, thereby it is endless and infinite long. Therefore, no one can tell you an exact number of decimal places for...
Question | How many decimal places does Pi have?
Square: That is quite easy: percent means nothing else than "per 100". Accordingly, 1 percent is 1 per 100 or in writing of fractions 1/100. So,...
Question | Convert Fractions into Percentages
Science5000: Normally, the median for an even number of values is the average (arithmetic mean) of both middle values. So, in your case for...
Chematik: Computing the covariance and correlation (the covariance is embedded in the correlation formula) depends on the fact, that the measurements...
Square: In some chewing gums, sorbitol is included as a sweetener. And sorbitol can be used as a laxative. Therefore, even the opposite could...

## Popular Topics

What is a light year?
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