Multiplication

Multiplication

The ability to multiply is a basic mathematical skill that everyone needs when taking any numeracy test. Essentially, multiplication is just repeated addition. For example, 5 + 5 is the same as 5 x 2.

Basic Multiplication

Learning how to multiply is actually pretty easy. The simplest way to multiply larger numbers is to “chunk” one of them into smaller parts. For example, if you were going to multiply a number by 15, you can easily work out 10 times the given number and 5 times the given number. Once you solve these problems, you simply add the answers together and have your solution.

A step by step process for multiplication is found here for the problem 55 x 16.

Step 1: Split the smaller of the two numbers into tens and units. So in this example, split 16 into 10 and 6.

Step 2: If necessary, split these into smaller chunks. For this example, 10 is easy to work with. You can split 6 into 5 and 1.

Step 3: Multiply the bigger number (45) by each of the chunks.

55 x 10 = 550

55 x 6 = 330

55 x 1 = 55

Step 4: Add all the answers together to find your solution.

550 + 330 + 55 = 935

How to Multiply Fractions

The next type of number you need to learn to multiply is fractions. When multiplying fractions, you are going to find the process is quite simple and involves two basic steps.

  • Multiply the top numbers (numerators)
  • Multiply the bottom numbers (denominators)

For example, multiply 2/5 by 4/9.

You multiply 2 x 4 and 5 x 9 to get an answer of 8/45.

Multiplying Decimals

You may also encounter situations where you need to multiply with decimals. Believe it or not, the process of multiplying decimals is also quite simple. Unlike adding or subtracting decimals, you don’t have to worry about lining the decimal points up. In fact, you don’t worry about the decimals at all until the end.

Step 1: Multiply the same way you would with whole numbers.

22.5 x 0.15 = 3375

Step 2: When finished, count the digits on the right side of the decimal in each of the original factors and add them together.

22.5 has one decimal point and 0.15 has two. You will add three to your solution.

Step 3: Put the decimal point in the answer so it has decimal places that are the same as the original factors.

The final answer is 3.375

Additional Multiplication Problems

When multiplying numbers, you may also find situations where you are tasked with multiplying exponents or multiplying matrices. While these processes are a bit more in depth, when you know the basics of multiplication, you can solve any equation given.

For example, to multiply exponents, you have to have bases that are the same. If the bases are the same, you will need to add the exponents given. For example:

For this equation, you have to add the exponents 2 + 3 to get a final solution of .

While there are a few rules you have to remember, multiplication is one of the easier processes to do.

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