Q&A #7499

Teachers' Lounge Discussion: Curious about fractions

T2T || FAQ || Teachers' Lounge || Browse || Search || T2T Associates || About T2T

View entire discussion
[<< prev] [ next >>]

From: MathFreak

To: Teacher2Teacher Public Discussion
Date: 2004091203:05:00
Subject: Why it works

WHY IT WORKS- I think it works because the product of two numbers is also the product of the L.C.M and H.C.F. of the two numbers. Say 1/28+ 1/42 LCM of 28 and 42: 28=2^2*3^0* 7^1 42=2^1*3^1*7^1 LCM= 2^2*3^1*7^1=4*3*7=84 HCF=2^1*3^0*7^1=2*1*7=14 HCF*LCM=2^2*2^1*3^1*3^0*7^1*7^1=28*42 Therefore,1/28+1/42= 1/84 *(3+2)=5/84 as also 1/LCM*HCF times (3*HCF+2*HCF)= 1/28*42 times(42+28) Since 3HCF+2HCF=5HCF=5*14=42+28=70. Hope this helps! Mathfreak

Post a reply to this message
Post a related public discussion message
Ask Teacher2Teacher a new question

[Privacy Policy] [Terms of Use]

Math Forum Home || The Math Library || Quick Reference || Math Forum Search

Teacher2Teacher - T2T ®
© 1994- The Math Forum at NCTM. All rights reserved.