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Scientific notation

math Maturity 11-13 Next article →

Sometimes numbers are just too big or too small to write easily. Imagine trying to write every zero in the mass of the Earth. It would take a long time and take up a lot of space.

Slide rule example2 with labels
Slide rule example2 with labels

Scientists and engineers use a special way to write these numbers. This is called scientific notation. It helps them write huge or tiny amounts very quickly. This method uses a base ten system to keep things simple. It makes hard math problems much easier to solve.

To use this system, you write a number called a significand. This is followed by ten raised to a power called an exponent.

Avogadro's number in e notation
Avogadro's number in e notation

In a special version called normalized notation, the significand stays between 1 and 10. For example, you would write 350 as 3.5 × 10^2. This makes it very easy to compare different numbers. You can quickly see which number is larger by looking at the exponent. If the exponent is negative, the number is very small, like 0.5 being 5 × 10^-1.

People have used tools to help with these big numbers for a long time. Engineers used slide rules to do math with logarithms.

Slide rule example2 with labels
Slide rule example2 with labels

Using these tools helped the use of scientific notation grow. Later, computers were built to handle these calculations too. In 1956, the first version of the Fortran language used a shortcut called E notation. This notation uses the letter "E" instead of writing out the power of ten. It is much easier to type on a computer keyboard.

Many different computer languages use this E notation today. Popular ones include Python, JavaScript, and C/C++.

Avogadro's number in e notation
Avogadro's number in e notation

Even older systems like the IBM 704 used these ideas. In 1960, a language called ALGOL 60 used a different symbol for ten. Some versions of ALGOL even used a Cyrillic letter to show the exponent. Today, most scientific calculators have a special mode called "SCI" for this. You can also find engineering notation, which uses exponents that are multiples of three.

Scientific notation also helps us be very precise with our measurements. It uses something called significant figures to show how exact a number is.

Avogadro's number in e notation
Avogadro's number in e notation

When you use normalized notation, you do not need extra zeros as placeholders. This makes it clear exactly how much you have measured. For example, an electron's mass is about 9.109 × 10^-31 kilograms. This notation helps us talk about the tiny parts of our world. It also helps us talk about the massive parts of our universe.

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