Pre-Algebra Demystified

In larger numbers, each group of three numbers (called aperiod) is sepa-

rated by a comma. The names at the top of the columns in Fig. 1-1 are called

period names.

To name a number, start at the left and going to the right, read each group of

three numbers separately using the period name at the comma. The word

‘‘ones’’ is not used when naming numbers.

EXAMPLE

Name 83,261,403.

SOLUTION

Eighty-three million, two hundred sixty-one thousand, four hundred three.

EXAMPLE

Name 308,657.

SOLUTION

Three hundred eight thousand, six hundred fifty-seven.

EXAMPLE

Name 413,000,000,025.

SOLUTION

Four hundred thirteen billion, twenty-five.

Math Note: Other period names after trillions in increasing order

are quadrillion, quintillion, sextillion, septillion, octillion, nonillion, and

decillion.

PRACTICE

Name each number:

1. 632


2. 8,


3. 413,


4. 33,605,493,

ANSWERS

1. Six hundred thirty-two


2. Eight thousand, five hundred six


3. Four hundred thirteen thousand, eight hundred fifty-seven

2 CHAPTER 1 Whole Numbers