“A bat and a ball cost $1.10 in total. The bat costs $1.00 more than the ball. How much does the ball cost?”Take a minute to think about it … Do you have the answer? Many people respond by saying that the ball must cost 10 cents. Is this the answer that you came up with? Although this response intuitively springs to mind, it is incorrect. If the ball cost 10 cents and the bat costs $1.00 more than the ball, then the bat would cost $1.10 for a grand total of $1.20. The correct answer to this problem is that the ball costs 5 cents and the bat costs — at a dollar more — $1.05 for a grand total of $1.10.So why do so many people answer incorrectly? The answer is that people often substitute difficult problems with simpler ones in order to quickly solve them. In this case, people seem to unconsciously substitute the “more than” statement in the problem (the bat costs $1.00 more than the ball) with an absolute statement (the bat costs $1.00). This makes the math easier to work with; if a ball...
