middle+school+math

How much pie did I eat? Would you like avocado pie? List a math website you think is fun.

include component="comments" page="middle school math" limit="10"

Can you complete the table? include component="comments" page="middle school math" limit="10"
 * input || output ||
 * 6 || 18 ||
 * 7 || 21 ||
 * 8 || 24 ||
 * 9 || ? ||