Gran, How Old Are You?

Using prime factorization helps answer the problem more efficiently because we know we need to find 5 numbers that multiplied together equals 111,111. So by finding the prime factorization, you can easily find the ages of Charlie, his siblings, and his mom. Also, when you find the prime factorization of 111,111 there are five numbers. One for each person. Using prime factorization also helps you know where to begin multiplying, and it helps you keep on track.