Scientific notation facts for kids
Scientific notation is a special way to write very large or very small numbers. Scientists and mathematicians use it to make these numbers much easier to read and work with. Imagine writing the distance to a faraway star, or the size of a tiny atom! Scientific notation helps turn these long numbers into shorter, simpler ones using decimals and powers of ten.
How Scientific Notation Works
The main idea behind scientific notation is to show how many zeros a number has by using a power of ten. You can write any number in scientific notation like this: a × 10b
In this formula:
- b is a whole number (it can be positive or negative). It tells you how many times 10 is multiplied by itself.
- a is a real number. It's called the significand.
Standard Form
When numbers are written in the standard (or "normalized") scientific notation, the number a is always between 1 and 10 (but not including 10). For example, 5.2 × 103 is in standard form, but 52 × 102 is not.
This standard way of writing numbers is very helpful because:
- It makes it easy to compare two numbers. You can quickly see which one is bigger by looking at the exponent b.
- The exponent b also tells you the number's order of magnitude, which is like its "size class." For example, a number with 106 is in the millions, and 10-3 is in the thousandths.
For negative numbers, a minus sign goes in front of a. For example, negative five is -5 × 100. If a number is between 0 and 1, the exponent b will be a negative number. For instance, 0.5 (one half) is -5 × 10-1.
The number zero (0) is just written as 0. It doesn't need to be in scientific notation.
See also
In Spanish: Notación científica para niños
