Multiplying by Fractions and Decimals

Date: 5/31/96 at 2:49:5
From: Marie Langley
Subject: math problem

My granddaughter wants to know, "What number is 3\10 more than .025?"

Thanks, Marie Langley

Date: 6/2/96 at 17:46:25
From: Doctor Brian
Subject: Re: math problem

Since your question involves both decimal and fractional 
representations for numbers, would you rather have the answer as a 
decimal or a fraction?  I will address both forms:

For decimals, we need to convert 3/10 to a decimal.  Since your 
granddaughter seems to have some familiarity with decimals, she is 
probably aware that 0.3 is officially read as "three tenths," and 
therefore *is* the decimal representation for 3/10.  At this point, we 
need simply to add the two decimals.  Lining up the place values gives 
us:

0.3
0.025
-----
0.325

For decimals, note that .025 may be read as "twenty-five thousandths."
Therefore, the question is now 3/10 + 25/1000.  Converting these to a 
common denominator of 1000 gives 300/1000 + 25/1000, which equals 
325/1000.  This fraction reduces to 13/40.  (Don't worry, 13/40 is the 
fraction equivalent for .325.)

-Doctor Brian,  The Math Forum
 Check out our web site!  http://mathforum.org/dr.math/