standard_description: Find all factor pairs for a whole number in the range 1–100. Recognize that a whole number is a multiple of each of its factors. Determine whether a given whole number in the range 1–100 is a multiple of a given one-digit number. Determine whether a given whole number in the range 1–100 is prime or composite.
problem_activity: Task
What is the last digit of $7^{2011}$?  Explain.
What are the last  two  digits of $7^{2011}$?  Explain.


aligns: no