Lesson 1: Numbers Through One Million

Property

Large numbers are read by grouping digits into periods of three, starting from the right, with commas separating each period. Each period has a name (e.g., million, thousand). Read the number within each period from left to right, followed by its name, omitting the name for the ones period.

Examples

• The number $452,198$ is read as "four hundred fifty-two thousand, one hundred ninety-eight". You read the number in the thousands period ($452$) and then the number in the ones period ($198$).

Property

To convert a number from word form to standard form, identify the value of each part of the name (e.g., "three hundred thousand" becomes $300,000$) and sum the values. To write it in expanded form, write the sum of the values of each digit. For example, "three hundred twenty-five" is $300 + 20 + 5$.

Examples

Given "fifty-two thousand, one hundred eight":

• Standard Form: $52,108$
• Expanded Form: $50,000 + 2,000 + 100 + 8$

Given "four hundred six thousand, seven hundred thirty":

• Standard Form: $406,730$
• Expanded Form: $400,000 + 6,000 + 700 + 30$

Given "nine hundred thousand, fifty-one":

• Standard Form: $900,051$
• Expanded Form: $900,000 + 50 + 1$

Explanation

This skill involves translating number names into their numerical representations. First, identify the place value terms like "thousand" and "hundred" to structure the number. Then, write the digits in their correct places, using zeros as placeholders for any missing values. Finally, express the number as a sum of each digit''s value to create the expanded form.