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Shortcuts in mathList any shortcuts you've discovered:P: Last edited by Toast (20061104 23:06:40) #2 20061104 22:27:50
Re: Shortcuts in math
im bored, so im giong to prove that. also, i wanted to add this this morning but i had to leave. for integer multiplications of 9 up to 9x10 the sum of the two digits always adds up to 9, and the first digit is always the multiplication  1 eg. 9*5 = 45, 4+5 = 9, 4=51 eg. 9*7 = 63, 6+3 = 9, 6=71 i find this one very helpful, although now its more a case of 'just knowing it' rather than applying this rule Last edited by lucadeltodesco (20061105 05:37:26) The Beginning Of All Things To End. The End Of All Things To Come. #3 20061105 08:39:21
Re: Shortcuts in mathI have a few towards the bottom of this page: Multiplication  Times Tables "The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  Leon M. Lederman #4 20061105 23:11:40
Re: Shortcuts in mathHmmm, I've only looked briefly at everything else apart from the forum; i think i'll go look around now :p #5 20061106 04:55:42
Re: Shortcuts in math
I'm not bored, but I'm going to disprove that. Why did the vector cross the road? It wanted to be normal. #6 20061106 05:35:15
Re: Shortcuts in mathPut the number in the middle and add anything more than a single digit to the beginning, I think was the rule. Boy let me tell you what: I bet you didn't know it, but I'm a fiddle player too. And if you'd care to take a dare, I'll make a bet with you. #7 20061107 06:31:52
Re: Shortcuts in math
You've used the rule in the wrong sense ; Using the rule Toast told us at the top of the forum; #8 20061107 08:22:52
Re: Shortcuts in mathOr just add neighboring digits as you go: "The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  Leon M. Lederman #9 20061107 08:40:37
Re: Shortcuts in mathIt's not a shortcut but more of a verification. If a number is evenly divisible by 3, the sum of it's digits is divisble by 3. #10 20061107 17:05:18
Re: Shortcuts in mathUm, ok you can put all the shortcuts you've ever found in math (not just arithmetic), just so long as this doesn't become an infinitely broad topic #11 20061108 01:24:15
Re: Shortcuts in mathToast, Character is who you are when no one is looking. #12 20061109 18:21:57
Re: Shortcuts in mathWhen you're using the Pythagorean theorem and you have sides of equal length: The base multiplied by the square root of the number of terms being sqrted gives the answer. *Only works to the power of 2* Last edited by Toast (20061109 18:22:53) 