document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1199918>Question 1199918</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Mulch is sold by the cubic yard.  To estimate number of cu. yds. needed for a circular bed, determine sq. footage.\r<BR>\n" );
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document.write( "Sq. footage = area of circle (pi * r^2).\r<BR>\n" );
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document.write( "3.1416 * 10^2 = 314 sq. ft. (10 ft. is example). \r<BR>\n" );
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document.write( "Convert sq. ft. to cu. ft.\r<BR>\n" );
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document.write( "Depth of mulch in inches.\r<BR>\n" );
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document.write( "314 * 4 (depth wanted)  = 1256\r<BR>\n" );
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document.write( "Divide by 324:  1256 / 324 = 3.876 = 4 cu. yds.\r<BR>\n" );
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document.write( "My question:  What does the 324 signify?\r<BR>\n" );
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document.write( "Note: 324 is used also for a square or rectangular bed (after obtaining sq. footage, multiply by depth of mulch needed, and again / by 324.)\r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #833898 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13200)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=greenestamps><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=greenestamps><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=833898\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "Apparently you are following a process defined by the resource you are using....<br><BR>\n" );
document.write( "If you are just interested in getting the answer without understanding why the process works, then okay.  But the process is a VERY POOR process for understanding how to calculate the number of cubic yards.<br><BR>\n" );
document.write( "And obviously, with the question you are asking, you do NOT understand why the defined process works.  And that is as it should be, because the process is NOT a good one.<br><BR>\n" );
document.write( "The problem is that the defined process uses square feet to find the area of the garden, and inches for the depth of the mulch; and it wants the volume of mulch in cubic yards.  Doing calculations with mixed units and then getting the final answer by dividing by the mystery number 324 is NOT good practice.<br><BR>\n" );
document.write( "Once again, if you do gardening for a living and just want a blind process for calculating cubic feet of mulch, then go ahead and us the defined process.<br><BR>\n" );
document.write( "But it is not good mathematical practice.<br><BR>\n" );
document.write( "The division by 324 (for any shape garden) comes from two places.<br><BR>\n" );
document.write( "(1) There are 12 inches in a foot; so when you multiply the area in square feet by the depth in inches, your resulting volume in cubic feet is too large by that factor of 12.<br><BR>\n" );
document.write( "and<br><BR>\n" );
document.write( "(2) There are 3^3 = 27 cubic feet in a cubic yard, so you need to divide the volume in cubic feet by 27 to get the volume in cubic yards.<br><BR>\n" );
document.write( "And 12*27 = 324 -- so the calculation by the defined process is too large by a factor of 324, so the last step in the defined process is to divide your answer in mixed units by 324.<br><BR>\n" );
document.write( "Mathematically a much better process....<br><BR>\n" );
document.write( "(1) area (in square feet) = 3.14(10^2) = 314<BR>\n" );
document.write( "(2) volume (in cubic feet) = area (in square feet) times depth (in feet) = 314(4/12) = 314(1/3) = 314/3<BR>\n" );
document.write( "(3) volume (in cubic yards) = volume (in cubic feet) divided by 27 (cubic feet per cubic yard) = (314/3)/27 = 314/81 = 3.876<br><BR>\n" );
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