# Find The Missing Number

**Computer Science**Level 3

You are given a list/array of \(n-1\) **unsorted** positive integers which you know to be the first \(n\) whole numbers with one of them missing.

About how many operations are needed (as a minimum) to determine which number is missing?

**Note:** For the purposes of this problem, one operation is defined as an addition, subtraction, multiplication, division, or element comparison.

**Just for fun**: Can you use your algorithm to find the missing number in this list of 9999 of the first 10,000 whole numbers?

**Your answer seems reasonable.**Find out if you're right!

**That seems reasonable.**Find out if you're right!

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