Verified Answer :

  • Identify the base \(b=4\) and the positional value of each digit \(d_i \cdot 4^i\).
  • Align digits with their respective powers: \(1\) at \(4^3\), \(3\) at \(4^2\), \(2\) at \(4^1\), and \(3\) at \(4^0\).
  • Construct the expanded form by summing these products: \(1 \cdot 4^3 + 3 \cdot 4^2 + 2 \cdot 4^1 + 3 \cdot 4^0\).
  • Verify the total as \(123\) in base 10; the final expanded form is \(\boxed{1 \cdot 4^3 + 3 \cdot 4^2 + 2 \cdot 4^1 + 3 \cdot 4^0}\).

Explanation

  1. Understanding Positional Notation and Base 4

The number \(1323_4\) is written in base 4. In any positional numeral system with base \(b\), a number represented by the sequence of digits \(d_n d_{n-1} \dots d_1 d_0\) has the value \(d_n \cdot b^n + d_{n-1} \cdot b^{n-1} + \dots + d_1 \cdot b^1 + d_0 \cdot b^0\). For the number \(1323_4\), the base is \(b = 4\), and the digits are \(d_3=1, d_2=3, d_1=2,\) and \(d_0=3\).

  1. Assigning Powers of 4 to Each Digit

To write the number in expanded form, we determine the power of 4 associated with each position, starting from the right (the units place, which corresponds to index 0):

  • The rightmost digit \(3\) is in the \(4^0\) position.
  • The digit \(2\) is in the \(4^1\) position.
  • The digit \(3\) is in the \(4^2\) position.
  • The leftmost digit \(1\) is in the \(4^3\) position.
  1. Constructing the Expanded Form

Now, we multiply each digit by its corresponding power of 4 and represent the value as a sum:
\(1323_4 = (1 \times 4^3) + (3 \times 4^2) + (2 \times 4^1) + (3 \times 4^0)\)
This expression is the expanded form of the number \(1323_4\).

  1. Final Expression and Verification

To verify the value in base 10, calculate each component:

  • \(1 \times 4^3 = 1 \times 64 = 64\)
  • \(3 \times 4^2 = 3 \times 16 = 48\)
  • \(2 \times 4^1 = 2 \times 4 = 8\)
  • \(3 \times 4^0 = 3 \times 1 = 3\)

Summing these gives \(64 + 48 + 8 + 3 = 123\). The expanded form is \(\boxed{1 \cdot 4^3 + 3 \cdot 4^2 + 2 \cdot 4^1 + 3 \cdot 4^0}\).

Examples

Expanded form is essential in computer science when working with different number systems, such as binary (base 2) or hexadecimal (base 16). For example, if a computer stores a color code as a base-16 number, understanding the expanded form allows you to convert that color code into a standard decimal (base 10) value that identifies the specific intensity of red, green, and blue components. By mastering the expanded form, you gain a foundational skill for understanding how data is structured and processed at the machine level.