Reading and Writing Large Numbers

Pre-Algebra · Axiom Academy

EXAMPLE Reading and Writing Large Numbers Convert between standard form, word form, and expanded form using the number 45,678,902. Take the large number below and write it three ways: in standard form (with commas), in expanded form (showing each digit's place value), and in word form . The key idea is to group the digits into periods — groups of three digits separated by commas. Nice work! You read and wrote 45,678,902 in standard, expanded, and word form by grouping its digits into periods. Remember: Periods are groups of three digits — ones, thousands, millions, billions, and so on. Commas separate periods — placed every three digits counting from the right, they make large numbers easy to read. Standard form uses commas: 45,678,902. Expanded form shows place values: 40,000,000 + 5,000,000 + 600,000 + 70,000 + 8,000 + 900 + 2. Word form uses the period names — "million," "thousand" — with no "and." Read each period as a three-digit number, then add its period name. These skills will help you work with large numbers throughout pre-algebra and beyond.

This is the written version of the interactive lesson above. See the full Pre-Algebra course.