What is the result of 4.21×10^-5 + 219.11? Show the work for the calculation.

1 answer

To perform the addition \( 4.21 \times 10^{-5} + 219.11 \), we need to express both numbers in the same format, preferably as decimal numbers for easier addition.

  1. Convert \( 4.21 \times 10^{-5} \) to decimal: \[ 4.21 \times 10^{-5} = 0.0000421 \]

  2. Now add \( 0.0000421 \) and \( 219.11 \): \[ 219.11 + 0.0000421 \approx 219.11 \] (Since \( 0.0000421 \) is a very small number compared to 219.11, it will not significantly change the result).

  3. Performing the exact addition:

    • Align the numbers for addition: \[ \begin{array}{r} 219.1100000 \
    • 0.0000421 \ \hline 219.1100421 \ \end{array} \]
  4. Thus, the final result is: \[ 4.21 \times 10^{-5} + 219.11 = 219.1100421 \]

  5. For reporting purposes, you might round this based on significant figures. However, since the first number contributes very little in terms of significant digits, the final answer could simply be: \[ 219.11 \]

Hence, the precise result is \( \mathbf{219.1100421} \) but depending on context, it may be simplified to \( \mathbf{219.11} \).