J John Whitaker Junior Member Joined May 9, 2006 Messages 89 Dec 16, 2007 #1 When calculating the LCM of two numbers like 13 & 32, (ans. 416), is there a shortcut method of reaching this answer without creating two long lists of numbers like 13, 26, 39, 52... and 32, 64, 96, 128... all the way to 416? Thank you.

When calculating the LCM of two numbers like 13 & 32, (ans. 416), is there a shortcut method of reaching this answer without creating two long lists of numbers like 13, 26, 39, 52... and 32, 64, 96, 128... all the way to 416? Thank you.

G galactus Super Moderator Staff member Joined Sep 28, 2005 Messages 7,216 Dec 16, 2007 #2 Re: LCM Yes, there is. Use their factorizations. \(\displaystyle 13=13\) \(\displaystyle 32=2^{5}\) Now, use the largest of each. Sinc there are only two, \(\displaystyle 13\cdot{2^{5}}=416\)

Re: LCM Yes, there is. Use their factorizations. \(\displaystyle 13=13\) \(\displaystyle 32=2^{5}\) Now, use the largest of each. Sinc there are only two, \(\displaystyle 13\cdot{2^{5}}=416\)

L Loren Senior Member Joined Aug 28, 2007 Messages 1,299 Dec 16, 2007 #3 Re: LCM Example: Find the LCM of 6,8,12 and 18. Factor each and express in exponential form. 6 = 2*3 8 = 2^3 12 = 2^2*3 18 = 2*3^2 To get the LCM select each base with its largest exponent and multiply them together. LCM is (2^3)(3^2) = 8*9 = 72.

Re: LCM Example: Find the LCM of 6,8,12 and 18. Factor each and express in exponential form. 6 = 2*3 8 = 2^3 12 = 2^2*3 18 = 2*3^2 To get the LCM select each base with its largest exponent and multiply them together. LCM is (2^3)(3^2) = 8*9 = 72.

J John Whitaker Junior Member Joined May 9, 2006 Messages 89 Dec 16, 2007 #4 Re: LCM Thank you. Got it.