Multiplication is basically finding the result of a sum that takes one number and asks what the total would be if that number is repeated a set number of times. For example, the sum “2 x 3" asks what the total would be if there were two groups of three. Work this out by imagining two groups of three and adding them together. This sum, “3 + 3,” would give you the correct answer, 6. Use a multiplication table to learn basic multiplication facts. Multiplication can also take place with three numbers. For example, the sum “2 x 3 x 9” requires you to take the result of the first two numbers multiplied together and multiply that by 9. The answer to this equation is 54.
Understanding the basic method of multiplying by 10 or 100 is simple and a necessary skill if you are going to get along in high school math. When multiplying a number by 10, you simply add “0” to the right of the original number. For example, “6 x 10” equals 60, and “65 x 10” equals 650. When you multiply a number by 100, you add two zeros to the right of the original number. Practice some basic multiplications by 10 or 100. This rule continues, so if you were multiplying by 1,000, you would add three zeros to the original number.
Long multiplication is the process of multiplying a two-digit or an even longer number by a two-digit number. This is done by splitting the sum into its constituent basic multiplications. For example, the sum “54 x 23” can be done by first multiplying 3 by both 4 and 5. The result of the first multiplication is 12, which means you write a “2” in the units column and a small “1” in the tens column. This 10 will be added on later. Then multiply 3 by 5 to get 15. The “5” goes in the tens column, with the spare 10 added to it to make a “6” in the tens column, and the “1” goes into the hundreds column. Repeat the same process with the “2” in the original number, multiplying it by 4 and then by 5. The lowest column you use for these sums is the tens column. 2 x 4 equals 8, so put an “8” in the next row down of the answer in the tens column. 2 x 5 is 10, meaning the “0” goes in the hundreds column and the “1” goes in the thousands column. You now have two numbers, 162 and 1,080. Add these to get the correct result, 1,242.
Multiplying negative numbers with positive numbers or other negative numbers can seem confusing at first. Remember the rule to get these questions right. If the numbers match, either two negative numbers or two positive numbers, you get a positive result. If they don’t match, you get a negative result. Multiply the numbers together and apply the rule to get the correct answer. “-5 x -5” has two negative numbers, so it has a positive answer, which is 25. “5 x -5” has one positive and one negative number, so the answer must be negative, -25.