Name large numbers using periods and commas
Large numbers are read by grouping digits into three-digit periods separated by commas — ones, thousands, millions — and reading each group followed by its period name, as taught in Grade 4 Eureka Math. For example, 4,567,890 is read as “four million, five hundred sixty-seven thousand, eight hundred ninety.” The ones period is never named. This systematic grouping makes multi-million numbers pronounceable and interpretable, connecting to place value understanding and real-world applications like population figures and distances.
Key Concepts
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. $$ \underbrace{123} {\text{Millions}} , \underbrace{456} {\text{Thousands}} , \underbrace{789} {\text{Ones}} $$.
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 ($198$).
Common Questions
How do you read large numbers using periods?
Group digits into sets of three from the right. Read each group as a three-digit number followed by its period name (millions, thousands). Skip the ones period name. Example: 2,400,000 = ‘two million, four hundred thousand.’
What is a period in a large number?
A period is a group of three digits separated by commas. From right to left: ones period (1–3), thousands period (4–6), millions period (7–9). Each period has a name.
Why do we use commas in large numbers?
Commas separate the three-digit periods, making large numbers easier to read and preventing the eye from losing count of digits. Without commas, 4567890 is much harder to read than 4,567,890.
What number does 5,003,060 represent?
Five million, three thousand, sixty. The 5 is in the millions period, 3 is in the thousands period, and 60 is in the ones period.
Why is the ones period not named when reading?
By convention, we do not say ‘ones’ at the end of a number. We simply state the digits: ‘five hundred forty-two’ not ‘five hundred forty-two ones.’ All other periods are named.