2013-03-24
Explanation
This comic features a child using mathematical reasoning to try to game the birthday-present system. The child exclaims "Daddy! It'''s approximately my birthday!" The father, rather than dismissing this, engages with the logic: since 1/365th of his life is birthdays, saying every day is his birthday is "within two orders of magnitude of the truth." He agrees that to simplify their lives, they can just say every day is his birthday, and they'''ll start tomorrow.
The humor lies in the father playing along with the child'''s specious reasoning -- treating a birthday as a rounding error. Being "within two orders of magnitude" means the claim is off by a factor of up to 100, which in science or engineering might sometimes be acceptable for rough estimates, but is absurd when applied to birthday celebrations. The father seems to genuinely consider this a reasonable approximation.
The punchline comes in the "Later..." panel when the child asks "Did you get me lots of presents?" and the father replies "Approximately" -- turning the child'''s own fuzzy math against him. If every day is approximately his birthday, then the father'''s gift-giving can be equally approximate (i.e., nonexistent). The votey panel simply shows someone exclaiming "Burn!" -- celebrating the father'''s clever reversal of the child'''s scheme.