Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Definition of Expanded Form: Expanded form is a way of writing a number to show the value of each digit. It is expressed as a sum of the place values of its digits. For example, the number is broken down into its parts based on where the digits sit.
Place Value Chart: To understand expanded form, imagine a table with three columns: Hundreds (H), Tens (T), and Ones (O). For a number like , you would place in the H column, in the T column, and in the O column. This visual helps you see that actually represents .
Value of Digits: The position of a digit determines its actual value. In a 3-digit number, the first digit from the left is multiplied by , the second by , and the third by . Visualizing base-10 blocks, a 'hundred' is a large square flat, a 'ten' is a long rod, and a 'one' is a small cube.
Writing the Sum: To write the expanded form, we connect the individual place values using the plus symbol (). For example, for the number , we identify the values as , , and , then write them as .
Zero as a Placeholder: When a number has a in a specific place, its value is . In expanded form, we can either write the or skip it, though writing it helps maintain the place value structure. For , the expanded form is , showing there are no tens (an empty Tens column in our mental chart).
Standard Form: This is the normal way we write numbers, like . Converting from expanded form () back to standard form () involves adding the values together or simply placing the digits in their correct H-T-O positions.
📐Formulae
💡Examples
Problem 1:
Write the number in expanded form.
Solution:
Step 1: Identify the place value of each digit. The digit is in the hundreds place, so its value is . \ Step 2: The digit is in the tens place, so its value is . \ Step 3: The digit is in the ones place, so its value is . \ Step 4: Write the sum of these values: .
Explanation:
We break the number down into its constituent parts (Hundreds, Tens, and Ones) and represent them as a mathematical addition expression.
Problem 2:
Convert the expanded form into standard form.
Solution:
Step 1: Look at the hundreds value: means there is a in the hundreds place. \ Step 2: Look at the tens value: means there is a in the tens place. \ Step 3: Look at the ones value: means there is a in the ones place. \ Step 4: Combine the digits to form the number: .
Explanation:
To find the standard form, we identify the single digit that belongs in each place value position and write them together as one number.