There are three signs associated with every fraction, one with the numerator, one with the denominator, and one with the fraction in general. But this can be hard to remember, because not all of the signs are always visible.

Read MoreThe absolute value operation turns any value inside it into its distance from the origin, essentially turning both positive and negative numbers into only positive numbers. Always calculate the value inside the absolute value first, then apply the absolute value last.

Read MoreThe vast majority of the numbers you’ll use in most math classes are called **real numbers**, and the whole universe of real numbers is what makes up the **Real Number System**. Let’s start with a diagram.

When we’re dealing with decimal numbers, rounding is an important tool that we need to know how to use. When we round, we always round to a certain decimal place.

Read MoreIt’s helpful to think about multiples and divisibility as two parts of the same idea. We know that 10 is “divisible” by 5 because when we do the division 10/5, the result 2 is a whole number. It’s the fact that the result is a whole number that proves that 10 is divisible by 5.

Read MoreWhen we multiply fractions, we multiply their numerators to find the numerator of the result, and we multiply their denominators to find the denominator of the result. When we divide fractions, we actually turn the division problem into a multiplication problem by turning the divisor upside down and changing the division symbol to a multiplication symbol at the same time.

Read MoreA common multiple of two positive whole numbers is a number that’s divisible by both of them. Their least common multiple is the smallest number that’s divisible by both of them.

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