stupid question in excel

[stuart harbour]

I was hoping I could attach my simple spreadsheet but it looks like that is not how this works. Anyway, I have 5 dollar and cents amounts added together in one row and five added together in another row. All numbers were keyed in by hand and include dollars and cents. (2 decimal points). When I subtract the smaller sum from the larger sum, the answer should be 75,946.78 Excel is returning the number I copied in below. I have checked every number by expanding the decimal out very far and they are all zero after the second number behind the decimal point. what is going on?? Any ideas?

<table width="225" border="0" cellpadding="0" cellspacing="0"><col width="225"><tr height="17"> <td class="xl65" style="height:12.55pt;width:168pt" width="225" height="17"> 2,527,588.2700000000000000 </td> </tr></table>less
<table width="225" border="0" cellpadding="0" cellspacing="0"><col width="225"><tr height="17"> <td class="xl65" style="height:12.55pt;width:168pt" width="225" height="17"> 2,451,641.490000000000000000 </td> </tr></table>
<table width="203" border="0" cellpadding="0" cellspacing="0"><col width="203"><tr height="17"> <td class="xl63" style="height:12.55pt;width:152pt" width="203" height="17"> 75,946.77999999980000 </td> </tr></table>

 

[shg]

Welcome to the board.

Base 10 decimals like 0.1 can't be stored exactly in the binary floating point format your computer uses, just like 1/3 is the repeating decimal 0.333...

Use ROUND to return the result to the nearest penny.