Technical Math For Dummies®

Chapter 5. Multiplication and Division: Everybody Needs Them

In This Chapter

• Understanding what multiplication and division are and how they work

• Performing big-number multiplication without a calculator

• Recognizing special cases that make multiplication and division easy

• Performing basic short and long division

Multiplication and division are parts of basic math, and they're as essential as addition and subtraction (see the preceding chapter). The good news is that just about everybody learned multiplication and division in elementary school. The bad news is that many people have forgotten how to do these operations. And if you didn't like math in your earlier school years, you probably forgot even faster.

Note: We're not going to make excuses for you — you need to be responsible for your own knowledge — but if you struggle with math fundamentals, it may not be entirely your fault. 1989 brought a considerable change to math teaching standards, with a decrease in learning fundamentals, so depending on your age, you may have been a victim of the early "new math" instruction and may not have gotten all the basics you needed.

If you had problems with multiplication and division in elementary, middle, or high school, be troubled no more. They're simpler than you may remember.

And they're important. Why? Because they're essential to your work, whether you multiply pounds of cement or bytes in a disk sector or divide fluids or flour. And the conversion of all weights and measures requires multiplication ...