Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
A 4-digit number is made up of four places: Thousands (), Hundreds (), Tens (), and Ones (). Imagine a place value chart where the leftmost column is the Thousands house and the rightmost is the Ones house.
The Face Value of a digit is the digit itself, regardless of its position. For example, in , the face value of is simply .
The Place Value of a digit depends on its position in the number. It is calculated by multiplying the digit by its position's value (). In , the place value of is .
Standard Form is the short way of writing a number using digits. In this form, we use commas to separate the thousands period from the rest, such as .
Expanded Form is a way to write a number as the sum of the place values of its digits. It shows how much each digit is worth. For example, becomes .
Zero () acts as a placeholder in both standard and expanded forms. If a place has a value of zero, like in , we write in the hundreds place to keep the other digits in their correct positions.
Numbers can be visualized using Base-10 blocks: a large 3D cube represents units, a flat square represents units, a vertical rod represents units, and a small single cube represents unit.
📐Formulae
💡Examples
Problem 1:
Write the number in expanded form.
Solution:
Step 1: Identify the place value of each digit.
- Digit is in Thousands place:
- Digit is in Hundreds place:
- Digit is in Tens place:
- Digit is in Ones place: Step 2: Write them as a sum. or .
Explanation:
To expand the number, we break it down into the value of each individual digit based on its position.
Problem 2:
Convert the following expanded form into standard form: .
Solution:
Step 1: Arrange the values in a place value chart.
- Thousands ():
- Hundreds ():
- Tens (): (since there is no multiple of provided)
- Ones (): Step 2: Combine the digits. Standard Form = .
Explanation:
When converting to standard form, ensure every place () is filled. Since there was no 'Tens' value in the sum, we must use as a placeholder.