Question

A number that can be written as a/b (a fancy word for a fraction)

Answer 1

Answer: Rational number

Step-by-step explanation

Some examples of rational numbers are 2/3 and 5/7. They are a ratio of two integers. The denominator cannot be zero.

If the decimal number terminates, aka stops, then it is rational

Some examples:

• 0.5 = 1/2
• 0.278 = 278/1000 = 139/500

If a decimal number has a repeated pattern, then it is rational.

Some examples:

• 0.33333333... = 1/3
• 0.23232323... = 23/99
• 0.16666666... = 1/6
• 0.273273273273... = 91/333

Use a horizontal bar over the portion that repeats.

Numbers like pi = 3.1415926535898... do not have a repeating pattern. The digits go on forever seemingly at random. We cannot write pi as a ratio of two integers. We can get somewhat close with approximations like 22/7 and 355/113, but we cannot get the exact value of pi with a number of the form a/b.

So this is why we consider numbers like pi to be irrational. Other examples of irrational numbers are things like
`√(2)` and
`\cos(37)`