Posts tagged math foundations
Adding and subtracting mixed numbers

We can add and subtract mixed numbers, each of which is the sum of a whole number and a fraction. When we need to add or subtract mixed numbers, we deal with the whole numbers separately from the fractions, and we find a common denominator for the fractions.

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What is a radical? What is a root?

You can think about radicals (also called “roots”) as the opposite of exponents. We already know that the expression x^2 with the exponent of 2 means “multiply x by itself two times”. The opposite operation would be “what do we have to multiply by itself two times in order to get x^2?”

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How to write numbers in scientific notation

With scientific notation, we’re able to express really really big numbers without all the digits and write a simpler number that quickly tells us how big the number is. So scientific notation can be used to express really, really big numbers, but it can also be used to express really, really small numbers.

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The identity numbers for addition and multiplication

Identity numbers are numbers that don’t change the “identity” of the original value. The identity for addition is 0. The identity for multiplication is 1. The reason is that you can add 0 to any number and it doesn’t change the original value, and you can multiply any number by 1 and it doesn’t change the original value.

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How to simplify fractions by cancelling common factors

The reason we want to reduce fractions to lowest terms is that even though a fraction like 630/945 is actually the same as 2/3, that isn’t obvious to us when we look at it since the numbers are so big. But if we simplify that larger fraction down to 2/3, then we’ll be able to easily tell that we have “2 out of 3 parts.”

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How to add, subtract, multiply, and divide decimal numbers

We can add, subtract, multiply, and divide decimal numbers. Addition and subtraction of decimal numbers works the same way as whole number addition and subtraction; we just need to make sure that we line up the decimal points.

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How to simplify repeating decimal numbers

There are two kinds of decimal numbers that go on forever and ever. Some decimals that go on forever eventually get to a point where a certain digit (or sequence of digits) repeats infinitely, but some decimal number that go on forever don’t repeat. We’ll look here at how to simplify repeating decimal numbers.

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