To find out how many sixth graders have red hair, you can calculate 5% of the total number of sixth graders.
5% can be expressed as a decimal: \[ 5% = 0.05 \]
Now, multiply this decimal by the total number of sixth graders: \[ 0.05 \times 100 = 5 \]
Therefore, 5 sixth graders have red hair.
The answer is 5.