Who can forget gems like these word problems from 3rd grade math class? Q: Jack walked from Santa Clara to Palo Alto. It took 1 hour 25 minutes to walk from Santa Clara to Los Altos. Then it took 25 minutes to walk from Los Altos to Palo Alto. He arrived in Palo Alto at 2:45 P.M. At what time did he leave Santa Clara? It was during those classes that our mathematics teachers taught us how to work backwards through the problem.