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When you write a long number, you use commas to separate groups of three numbers. For example, here’s about as long a number as you’ll ever see:

Table 3-4 shows a larger version of the place-value chart.

Table 3-4 A Place-Value Chart Separated by Commas

Quintillions	Quadrillions	Trillions	Billions	Millions	Thousands	Ones
234	845	021	349	230	467	304

This version of the chart helps you read the number. Begin all the way to the left and read, “Two hundred thirty-four quintillion, eight hundred forty-five quadrillion, twenty-one trillion, three hundred forty-nine billion, two hundred thirty million, four hundred sixty-seven thousand, three hundred four.”

When you read and write whole numbers, don’t say the word and. In math, the word and means you have a decimal point. That’s why, when you write a check (does anyone still write checks?), you save the word and for the number of cents, which is usually expressed as a decimal or sometimes as a fraction. (I discuss decimals in Chapter 13.)