WOLFRAM|DEMONSTRATIONS PROJECT

Making Change for a Purchase

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make change
$10
0
1
$5
0
1
2
3
$1
0
1
2
3
4
50¢
0
1
25¢
0
1
2
3
10¢
0
1
2
3
4
5¢
0
1
2
3
4
1¢
0
1
2
3
4
next customer
Total Purchase $16.75
Tendered
Change $0.00
Suppose you work in an old-fashioned country general store without a newfangled computerized cash register. You have to work out the change for a purchase in your head. The "Change" display turns red when you select the right amount.
Here's how to do it. Suppose the purchases total $5.33 and the customer hands you a $10 bill. Imagine adding 2¢ to the $5.33 to get $5.35; then add 5¢ to bring the total to $5.40; 10¢ to get to $5.50; 50¢ (or 2 quarters) to get to $6.00; and finally add four $1 bills. This adds up to a total change of $4.67.