# Finding exponentials with a calculator **URL:** \ **Category:** Factual Questions\ **Created:** [August 19, 2017, 3:40pm UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094 "2017-08-19T15:40:51Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![dougie\_monty](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@dougie\_monty](https://boards.straightdope.com/u/dougie_monty)\ **Post date:** [August 19, 2017, 3:40pm UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/1 "2017-08-19T15:40:51Z")
I wanted to find “4 to the 7th power” (from a line of a song by C. W. McCall) on my Smartphone calculator. It has buttons for e to the x power, x squared, and y to the x power. Can any of those find the exponential I want? ---
**Author:** ![Grey](https://avatars.discourse-cdn.com/v4/letter/g/b782af/32.png) [@Grey](https://boards.straightdope.com/u/Grey)\ **Post date:** [August 19, 2017, 3:42pm UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/2 "2017-08-19T15:42:58Z")
y[sup]x[/sup] will give you 4[sup]7[/sup], though my phone presents it as x[sup]y[/sup] ---
**Author:** ![dougie\_monty](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@dougie\_monty](https://boards.straightdope.com/u/dougie_monty)\ **Post date:** [August 19, 2017, 4:10pm UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/3 "2017-08-19T16:10:33Z")
Thanks! It worked. 🙂 (16,384) ---
**Author:** ![DSYoungEsq](https://avatars.discourse-cdn.com/v4/letter/d/c6cbf5/32.png) [@DSYoungEsq](https://boards.straightdope.com/u/DSYoungEsq)\ **Post date:** [August 20, 2017, 4:34am UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/4 "2017-08-20T04:34:52Z")
Whether the calculator uses y[sup]x[/sup] or x[sup]y[/sup] usually depends upon what order you must enter the arguments to get the right answer. ---
**Author:** ![OldGuy](https://avatars.discourse-cdn.com/v4/letter/o/3bc359/32.png) [@OldGuy](https://boards.straightdope.com/u/OldGuy)\ **Post date:** [August 20, 2017, 5:18am UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/5 "2017-08-20T05:18:53Z")
I do hope you know what 4 to the 7th power means so you could have multiplied 4_4_4_4_4_4_4= much faster than you could have posted here to ask. ---
**Author:** ![yarblek](https://avatars.discourse-cdn.com/v4/letter/y/71e660/32.png) [@yarblek](https://boards.straightdope.com/u/yarblek)\ **Post date:** [August 20, 2017, 5:39am UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/6 "2017-08-20T05:39:36Z")
> [@OldGuy](#): > > I do hope you know what 4 to the 7th power means so you could have multiplied 4_4_4_4_4_4_4= much faster than you could have posted here to ask. Need answer fast!!! 😃 ---
**Author:** ![standingwave](https://avatars.discourse-cdn.com/v4/letter/s/9de0a6/32.png) [@standingwave](https://boards.straightdope.com/u/standingwave)\ **Post date:** [August 20, 2017, 7:47am UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/7 "2017-08-20T07:47:13Z")
> [@OldGuy](#): > > I do hope you know what 4 to the 7th power means so you could have multiplied 4_4_4_4_4_4_4= much faster than you could have posted here to ask. Or he could have taken the log (any base) of 4, multiplied by 7, and taken the antilog (same base) of the result. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [August 20, 2017, 2:21pm UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/8 "2017-08-20T14:21:13Z")
> [@OldGuy](#): > > I do hope you know what 4 to the 7th power means so you could have multiplied 4_4_4_4_4_4_4= much faster than you could have posted here to ask. Or the shortcut on prett much any calculator I’ve used “4 x = = = = = =” (Hit “4” then “x,” then equals six times.) ---
**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\ **Post date:** [August 20, 2017, 2:34pm UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/9 "2017-08-20T14:34:56Z")
Isn’t the rule that you must depict the number with exactly four 4’s? How about √4sup[/sup] ---
**Author:** ![dougie\_monty](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@dougie\_monty](https://boards.straightdope.com/u/dougie_monty)\ **Post date:** [August 20, 2017, 4:01pm UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/10 "2017-08-20T16:01:32Z")
> [@standingwave](#): > > Or he could have taken the log (any base) of 4, multiplied by 7, and taken the antilog (same base) of the result. Perhaps I could, but I’m not that good at math. I don’t know offhand the “logs” of numbers. ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [August 20, 2017, 4:05pm UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/11 "2017-08-20T16:05:13Z")
Assuming you do not have an exponential key you could have done ln(7) ANS x 4 e^(ANS) ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [August 20, 2017, 4:11pm UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/12 "2017-08-20T16:11:42Z")
> [@DSYoungEsq](#): > > Whether the calculator uses y[sup]x[/sup] or x[sup]y[/sup] usually depends upon what order you must enter the arguments to get the right answer. I don’t think this is correct (he says hesitantly). I’ve seen calculators where the “raise a number to a power” button is labeled as **y[sup]x[/sup]** or as **x[sup]y[/sup]** or as **^** , but I don’t think that had anything to do with the way the button worked. Although I’m not familiar with all the different calculator models out there. > [@Saint\_Cad](#): > > Assuming you do not have an exponential key you could have done > ln(7) > ANS x 4 > e^(ANS) Right, but when’s the last time you saw a calculator without an exponential key, but that did have a ln key and an e^ key? ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [August 20, 2017, 4:24pm UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/13 "2017-08-20T16:24:27Z")
The standard Android calculator has a ^ key. 4^7=16384 ---
**Author:** ![eschereal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschereal/32/18939_2.png) [@eschereal](https://boards.straightdope.com/u/eschereal)\ **Post date:** [August 20, 2017, 4:24pm UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/14 "2017-08-20T16:24:58Z")
> [@Saint\_Cad](#): > > Assuming you do not have an exponential key you could have done > ln(7) > ANS x 4 > e^(ANS) umm, no? That would be 7[sup]4[/sup]. ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [August 20, 2017, 4:28pm UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/15 "2017-08-20T16:28:48Z")
> [@eschereal](#): > > umm, no? That would be 7[sup]4[/sup]. :smack: Right. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [August 20, 2017, 4:33pm UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/16 "2017-08-20T16:33:53Z")
As a cross check take 16384 and raise to 1/7 power 16384^.142857 = 3.999994 slight rounding error but otherwise it gives the original base number of 4 ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [August 20, 2017, 4:44pm UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/17 "2017-08-20T16:44:14Z")
16384^(1/7) = 4 Parentheses resolves the rounding error Androids calculator isn’t bad. The root key seems to only do square roots. Raising a base number to a fractional power resolves that problem. ---
**Author:** ![dougie\_monty](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@dougie\_monty](https://boards.straightdope.com/u/dougie_monty)\ **Post date:** [August 21, 2017, 3:34pm UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/18 "2017-08-21T15:34:56Z")
FWIW, I don’t have a ^ key. I do have a “x!” key, whatever that is. ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [August 21, 2017, 3:43pm UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/19 "2017-08-21T15:43:14Z")
> [@dougie\_monty](#): > > FWIW, I don’t have a ^ key. I do have a “x!” key, whatever that is. Factorial. For example, pressing **5** **x!** gives you 5!, which is 1 x 2 x 3 x 4 x 5 (all the counting numbers up to 5, multiplied together). One thing this is used for is to give you all the different orders (called “permutations”) that five different objects could be in. If you don’t have a ^ key, do you have a differently-labeled key that does exponents (like **x[sup]y[/sup]**)? ---
**Author:** ![dougie\_monty](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@dougie\_monty](https://boards.straightdope.com/u/dougie_monty)\ **Post date:** [August 21, 2017, 8:51pm UTC](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094/20 "2017-08-21T20:51:49Z")
> [@Thudlow\_Boink](#): > > Factorial. For example, pressing **5** **x!** gives you 5!, which is 1 x 2 x 3 x 4 x 5 (all the counting numbers up to 5, multiplied together). > > One thing this is used for is to give you all the different orders (called “permutations”) that five different objects could be in. > If you don’t have a ^ key, do you have a differently-labeled key that does exponents (like **x[sup]y[/sup]**)? No, but I do have y to the x power… [Next page](https://boards.straightdope.com/t/finding-exponentials-with-a-calculator/794094.md?page=2)