Question 2.1: Convert 100100112 to decimal.

Step 1: Write down the binary number, leaving space between the bits.
\begin{matrix} 1 & 0 & 0 & 1 & 0 & 0 & 1 & 1 \end{matrix}
Step 2: Double the high-order bit and copy it under the next bit.
\begin{matrix} 1 & 0 & 0 & 1 & 0 & 0 & 1 & 1 \\ & 2 & & & & & & \\\frac{\times 2}{2} & & & & & & & \end{matrix}

Step 3: Add the next bit and double the sum. Copy this result under the next bit.

Step 4: Repeat Step 3 until you run out of bits.

When we combine hextet grouping (in reverse) with the double-dabble method, we find that we can convert hexadecimal to decimal with ease.