Sure, let's solve this step-by-step.
1. Identify the largest 4-digit number:
The largest 4-digit number is 9999.
2. Identify the target number:
The target number given in the question is 67,890.
3. Find out how much to add to the largest 4-digit number to reach the target number:
To do this, subtract the largest 4-digit number from the target number.
Let's outline it mathematically:
[tex]\[
\text{Value to add} = \text{Target number} - \text{Largest 4-digit number}
\][/tex]
Substitute the numerical values:
[tex]\[
\text{Value to add} = 67,890 - 9999
\][/tex]
4. Compute the result:
We find that:
[tex]\[
67,890 - 9999 = 57,891
\][/tex]
So, you need to add 57,891 to the largest 4-digit number, 9999, to get 67,890. The final answer is 57,891.