# Math

Home » Math

## Which one is the numerator? Fractions

By | 2017-07-29T16:41:01+00:00 July 29th, 2017|Math|

A pie cut into thirds The numerator of a fraction is the number on the top, just as the denominator is the number on the bottom. In the fraction 1/2, the numerator is one, and in the fraction 3/4, the numerator is three. The numerator tells you how many pieces of pie you're going to get to eat. If the [...]

## What are logarithms? Numbers and math

By | 2017-07-29T16:38:58+00:00 July 29th, 2017|Math|

Earthquake in Peru Logarithms are a way of writing numbers using exponents. "Log 100" means the exponent you'd need to use to get 100 starting from 10. That would be 2, because 102 = 100. So Log 100 = 2, and Log 1000 = 3. Logarithms are useful for thinking about big numbers in general terms, when [...]

## What is infinity? Math and numbers

By | 2017-07-29T16:35:21+00:00 July 29th, 2017|Math|

A number line is infinite in both directions. When we think about the number line, we can see that there's no end to it - both in the negative direction and in the positive direction, the numbers go on forever. You can always add one more. We call that forever "infinity". But infinity's more [...]

## What are fractions? – Math

By | 2017-07-29T16:27:42+00:00 July 29th, 2017|Math|

A fraction of a pie When we first thought about the number line, we counted only in whole numbers - we went straight from zero to one to two to three. But what if we wanted to stop in between the numbers? If we stop halfway between 0 and 1, we call that number a half [...]

## What are factors? Factors and prime numbers

By | 2017-07-29T15:06:47+00:00 July 29th, 2017|Math|

Three is a factor of nine. A factor is a whole number that fits evenly into another whole number. For example, 3 is a factor of 9, because you can fit 3 evenly three times into 9: 3 x 3 = 9. Four is not a factor of 9, because there is no way to [...]

## Exponents – numbers and math

By | 2017-07-29T15:04:31+00:00 July 29th, 2017|Math|

This is a square. The darker purple line is the perimeter of the square. Using exponents is a short way of saying "multiply the number by itself." The little number up above tells you how many times to multiply the number by itself. So 102 means 10 x 10, or 100. We call this "10 [...]

## Which one is the denominator? Fractions

By | 2017-07-29T14:52:00+00:00 July 29th, 2017|Math|

A pie cut into thirds The denominator of a fraction is the number on the bottom (the top is the numerator). In the fraction 1/2, the denominator is 2. In the fraction 45/66, the denominator is 66. And in the fraction 2/3, the denominator is 3. For whole numbers, the denominator is always one, so when we say "three", [...]

## Decimals and fractions – Numbers

By | 2017-07-29T14:49:06+00:00 July 29th, 2017|Math|

A number line is infinite in both directions. Decimals, like fractions, are a way of describing points on the number line that fall in between the whole numbers. If you were using fractions, you'd say that the point halfway between 1 and 2 was 1 1/2. In decimals, you'd call that same point 1.5. Each digit after [...]

## Common denominator – fractions

By | 2017-07-29T14:22:51+00:00 July 29th, 2017|Math|

A fraction of a pie If you want to add two fractions together, both fractions must have the same denominator. That's okay if you want to add 1/9 and 4/9 = 5/9. But what if you need to add 1/9 and 4/7? How can you add them? You need to change one or both of those fractions so [...]

## Big numbers – billions and trillions

By | 2017-07-29T14:24:54+00:00 July 29th, 2017|Math|

An infinite distance: stars in the sky A 1 with one zero next to it means 1 multiplied by 10, or ten. A 1 with two zeros next to it means 1 x 100, or in exponents 102, or a hundred. And a 1 with three zeros next to it means 1 x 1000, or 103, [...]