ForumTechnical Corner ► Math Problem Thread
But why do I do 10^6?
  
Ten options for the first digit, ten options for the second digit, ten options for the third digit, etc.

Ten multiplied by itself six times, one for each digit. 10^6.
  
Oh I overthought it
  
When thinking of permutations, it can be helpful to draw a tree (mentally or physically), representing each possibility.

Ten options for the first digit = ten branches

Ten options for the second digit = ten branches on each branch

Ten options for the third digit = ten branches on each branch branch.

When thinking about combinations, pray to god you understand how they work, because visual aid can't exactly help
  
Combinatorics is the hardest part of discrete math, imo
  
How do I check the battery level on a TI-84 Plus calculator?
  
Isn't it just in the top corner? Or is that only on the CE?
  
the icon is only on the CE since it's rechargable. since the TI-84 plus is powered by normal AAA batteries, i don't think there's a way to check the power unless you have a battery checker/multimeter. kinda just wait for it to die i think. if you're worried you can carry spares.

there's also ALLEGEDLY a program you could use to check the battery. i haven't checked it out since i don't have the Plus, but reddit says it's okay. http://tibasicdev.wikidot.com/hexcodes#toc63
  
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