Understanding:
First of all, each time Xavier buys lunch he saves a nickel. That means if he buys lunch twice, he is saving 2 nickels, buys 3 times he saves 3 nickels, and so on. To solve this problem we can simply add the times he bought lunch and that will equal the value of nickles he saved so far.
Solution:
First-week savings = 4 nickels
Second-week savings = 2 nickels
Simply, adding those together gives us 6 nickels.
