Challenger Elementary School has 800 students. Every Wednesday, 12, percent of the students stay after school for Chess Club.

To find out how many students stay after school for Chess Club at Challenger Elementary School on Wednesdays, you'll need to calculate 12% of the total number of students.

Here's how to calculate it step by step:
1. Convert 12% to decimal form by dividing it by 100: 12/100 = 0.12
2. Multiply the decimal form (0.12) by the total number of students (800): 0.12 * 800 = 96

Therefore, 96 students stay after school for the Chess Club at Challenger Elementary School on Wednesdays.