A way of writing numbers that shows place value as in 639 = 600 + 30 + 9.

• A. Standard Form
• B. Expanded Notation
• C. Scientific Notation
• D. Partial Notation

Answer: (B)

The idea being tested is showing a number by breaking it into the values of its digits according to place value. In 639, the 6 stands for hundreds (600), the 3 for tens (30), and the 9 for ones (9). Writing it as 639 = 600 + 30 + 9 shows exactly how each digit contributes to the total, which is what expanded notation does. This helps you see why the digits have those values and makes addition and place-value reasoning easier. Other forms either keep the number in a single string of digits (standard form) or use scientific notation, which focuses on a different representation and doesn’t display the place-value breakdown as a sum. So the way shown is expanded notation.