Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Introduction to 4-Digit Numbers: A 4-digit number consists of four places: Thousands (), Hundreds (), Tens (), and Ones (). The smallest 4-digit number is and the largest is . Visually, you can imagine these numbers represented by blocks: a large cube for , a flat square for , a rod for , and a small cube for .
Face Value: The face value of a digit is the digit itself, regardless of its position in a number. For example, in the number , the face value of is simply . It is the visual identity of the digit on the page.
Place Value: The place value of a digit depends on its position in the number. In a place value chart, moving from right to left, the values of the places are (Ones), (Tens), (Hundreds), and (Thousands). For example, in , the digit is in the Hundreds place, so its place value is .
Expanded Form: Writing a number as the sum of the place values of its digits is called expanded form. It helps visualize the 'weight' of each digit. For example, the number is written as .
Standard Form: This is the normal way of writing numbers using digits. To convert expanded form to standard form, we place each digit in its respective column. For instance, becomes . If a place is missing (like no 'Tens'), we must use as a placeholder.
Successor and Predecessor: The successor is the number that comes just after a given number (). The predecessor is the number that comes just before a given number (). On a horizontal number line, the predecessor is always to the left and the successor is always to the right of the given number.
Comparing Numbers: To compare two 4-digit numbers, start by comparing the digits in the Thousands place. If they are the same, move to the Hundreds, then Tens, and finally Ones. We use symbols like (greater than), (less than), or (equal to). For example, because at the Tens place, .
📐Formulae
💡Examples
Problem 1:
For the number , find the face value and place value of the digit . Also, write the number in expanded form.
Solution:
- Face Value: The digit is , so its face value is .
- Place Value: The digit is in the Hundreds () place. Therefore, Place Value = .
- Expanded Form: Sum of place values = .
Explanation:
We identify the position of each digit using a place value chart () and then apply the definitions for face value and place value.
Problem 2:
Write the standard form of and find its successor.
Solution:
- Standard Form: Thousands = , Hundreds = (since no hundred value is given), Tens = , Ones = . The number is .
- Successor: .
Explanation:
To write the standard form, we must ensure every place value is represented. Since there was no 'Hundreds' term, we use as a placeholder. The successor is then found by adding .