Suppose jellybeans cost
.99 per pound and you bought exactly a
quarter-pound (0.25 pounds). How much money should you give the
clerk? [Assume that there is no tax on the purchase.]
1.99 (2 decimal places)
0.25 (2 decimal places)
49 75 (4 decimal places)
The answer is
.4975 . If you had changed
.99 into pennies when
you started, then you would owe 49.75 (49 3/4) pennies. You could take
a penny, divide it into four equal parts, and give the clerk three of them
(along with the 49), but I don't think the clerk will be very happy.
Instead, we usually round the cost to the nearest penny. That means
.4975 will be rounded to the nearest
of a dollar
(penny or cent).
In the previous example, you will pay either
.50 (the amount
just below the calculated true price and the amount just above the
calculated true price). Look at the number line drawn below.
Is 0.4975 (♦) closer to 0.49 or 0.50?