How to Enable Automatic Recalculation

*To*: mathgroup at smc.vnet.net*Subject*: [mg109817] How to Enable Automatic Recalculation*From*: Victor Roberts <xxx at lighting-research.com>*Date*: Wed, 19 May 2010 07:01:59 -0400 (EDT)

I'm new to Mathematica, so perhaps there is a simple answer to this question. How to I set Mathematica so that when I change the value assigned to a variable it will automatically change all later calculations that use that variable. For example, if I set a = 5 and b = 3 + a I would like the value of b updated each time I change the value of a. Right how, I need to recalculate each and every expression that uses the variable a if I change its value. There must be a better way. -- Vic Roberts Replace xxx with vdr in e-mail address.