Basic Math & Pre-Algebra

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How to Find the Factors of a Number

The factors of a number are all those numbers that can divide evenly into the number with no remainder. The greatest factor of a number is the number itself, so you can always list all the factors of any [more…]

How to Increase the Terms of a Fraction

Even if fractions look different, they can actually represent the same amount; in other words, one of the fractions will have increased terms compared to the other. You may need to increase the terms of [more…]

How to Reduce a Fraction to Its Lowest Terms

Even if fractions look different, they can actually represent the same amount; in other words, one of the fractions will have reduced terms compared to the other. You may need to reduce the terms of fractions [more…]

How to Convert a Mixed Number to an Improper Fraction

Although mixed numbers are great for everyday use, it is often easier to work with improper fractions when you want to solve math problems. To convert a mixed number to an improper fraction, follow these [more…]

How to Cross-Multiply Two Fractions

Cross-multiplication is a handy math skill to know. You can use it for a few different purposes. For example, you can compare fractions and find out which is greater. [more…]

How to Divide Fractions by Finding the Reciprocal

Dividing fractions is just as easy as multiplying them. In fact, when you divide fractions, you really turn the problem into multiplication by using a reciprocal. [more…]

How to Find the Sum of Fractions with the Same Denominator

When you add two fractions that have the same denominator (bottom number), you simply add the numerators (top numbers) together and leave the denominator unchanged. [more…]

How to Add Fractions with Different Denominators

When the fractions that you want to add have different denominators, there are a few different ways you can do it. Here, you’ll learn the easy way, then a quick trick that works in a few special cases, [more…]

Use Rectangles to Identify Composite Numbers

Some numbers can be placed in rectangular patterns. Mathematicians probably should call numbers like these “rectangular numbers,” but instead they chose the term composite numbers. For example, 12 is a [more…]

How to Subtract Numbers

Subtraction is usually the second operation you discover, and it’s not much harder than addition. In fact, you can subtract larger numbers by stacking them in columns, similar to how you add large numbers [more…]

How to Multiply Numbers

To multiply numbers, you need to know how to work with the different times signs as well as parentheses. If you multiply large numbers, you also need to know how to stack them in columns, so that you can [more…]

How to Find the Least Common Multiple

The least common multiple (LCM) of a set of numbers is the lowest positive number that is a multiple of every number in that set. For example, the LCM of the numbers 2, 3, and 5 is 30 because [more…]

How to Convert an Improper Fraction to a Mixed Number

Although improper fractions are great for solving math problems, the results may be easier for people to understand if you first convert them to mixed numbers. To convert an improper fraction to a mixed [more…]

A Closer Look at Pi (p)

The symbol p (pi — pronounced pie) is a Greek letter that stands for the ratio of the circumference of a circle to its diameter. Here’s the approximate value of p: [more…]

How to Subtract Fractions with the Same Denominator

Subtracting fractions with the same denominator (bottom number) is easy. When the denominators are the same, you can just think of the fractions as pieces of cake. [more…]

Move the Decimal Point to Change a Number’s Value

When you’re working with whole numbers, you can multiply or divide any number by 10 just by moving the decimal point to the right or left, respectively. When you multiply by moving the decimal point to [more…]

How to Round Decimals

Rounding decimals works almost exactly the same as rounding numbers. You will usually need to round a decimal either to a whole number or to one or two decimal places. [more…]

How to Add Decimals

Adding decimals is almost as easy as adding whole numbers. As long as you set up the problem correctly, you’re in good shape. To add decimals, follow these steps: [more…]

How to Subtract Decimals

Subtracting decimals is almost as easy as subtracting whole numbers. As long as you set up the problem correctly, you’re in good shape. Here’s how you subtract decimals: [more…]

How to Multiply Decimals

Multiplying decimals is different from adding and subtracting them in that you don’t have to worry about lining up the decimal points. In fact, the only difference between multiplying whole numbers and [more…]

How to Divide Decimals

When you know how to do long division, figuring out how to divide decimals is easy. However, unlike dividing whole numbers, with decimals, you have to add trailing zeros in the dividend and you also have [more…]

How to Use Trailing Zeros and Leading Zeros in a Decimal Number

When you work with decimal numbers, you need to understand the difference between trailing zeros and leading zeros, as well as how they affect the value of the number. [more…]

How to Convert between Percents and Decimals

It is easy to convert percents to decimals and decimals to percents. For example, to convert a percent to a decimal, you drop the percent sign (%) and move the decimal point two places to the left. That’s [more…]

How to Convert from Percents to Fractions

Converting percents to fractions is fairly straightforward. Remember that the word percent means “out of 100.” So changing percents to fractions naturally involves the number 100. [more…]

How to Split Up a Pizza into Unequal Amounts

You may have to add or subtract fractions in word problems that involve splitting up part of a whole into unequal amounts. For example, consider the following pizza problem: [more…]


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