I'm following JBDad to Wikipedia so I can understand what his son was doing. I thought I had a good grasp of math before reading
2^3 x 1 + 2^2 x 0 + 2^1 x 0 + 2^0 x 1 converts binary

It left me scratching my head going "Huh?" confused

DD6 was doing Logic Safari today and loving it. It led to a good discussion about the importance of checking your answer at the end to make sure it agrees with the given facts.