# Complex math calculation **URL:** \ **Category:** General\ **Tags:** smart-contracts\ **Created:** [March 21, 2022, 6:50am UTC](https://forum.algorand.co/t/complex-math-calculation/6304 "2022-03-21T06:50:36Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![hungpq](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@hungpq](https://forum.algorand.co/u/hungpq)\ **Post date:** [March 21, 2022, 6:50am UTC](https://forum.algorand.co/t/complex-math-calculation/6304/1 "2022-03-21T06:50:36Z")
AVM currently now support almost like other blockchain platform so there are more and more defi app to follow in the upcoming days. So i want to ask how to perfrom complex pow math (with large number). i can see bytesadd, … but cant seem to find with pow calculation. if can, can you give me example of how to use them in PyTeal (what happend if overflow, etc…) Thanks for reading. ---
**Author:** ![Ben](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.algorand.co/ben/32/1979_2.png) [@Ben](https://forum.algorand.co/u/Ben)\ **Post date:** [March 21, 2022, 11:09am UTC](https://forum.algorand.co/t/complex-math-calculation/6304/2 "2022-03-21T11:09:29Z")
Hi Hung, I think the `exp` opcode might be what you’re looking for in the case of `pow` Overflow would result in termination of the program and failure of the transaction. Ben ---
**Author:** ![hungpq](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@hungpq](https://forum.algorand.co/u/hungpq)\ **Post date:** [March 21, 2022, 11:11am UTC](https://forum.algorand.co/t/complex-math-calculation/6304/3 "2022-03-21T11:11:42Z")
thanks for your answer what is the different between `exp` and `expw`? it would be great if you can give some example. and also i want to know how to do bit shift in teal? for example i want to express the value 4 and 7 in a single bytes, each value can have 64 bit length (ex: 00000000000000040000000000000007) ---
**Author:** ![fabrice](https://avatars.discourse-cdn.com/v4/letter/f/5fc32e/32.png) [@fabrice](https://forum.algorand.co/u/fabrice)\ **Post date:** [March 21, 2022, 9:06pm UTC](https://forum.algorand.co/t/complex-math-calculation/6304/4 "2022-03-21T21:06:21Z")
The output of `expw` is 128 bits (=16 bytes). The difference between `exp` and `expw` is the same as the difference between `mul` and `mulw`. > [@hungpq](#): > > and also i want to know how to do bit shift in teal? for example i want to express the value 4 and 7 in a single bytes, each value can have 64 bit length (ex: 00000000000000040000000000000007) I guess `00000000000000040000000000000007` is in hexadecimal. If yes, this is 128 bits = 16 bytes. So this _cannot_ be represented by an uint64. If this was the output of `expw`, one of the output of `expw` would be 4, the other 7. ---
**Author:** ![hungpq](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@hungpq](https://forum.algorand.co/u/hungpq)\ **Post date:** [March 21, 2022, 11:50pm UTC](https://forum.algorand.co/t/complex-math-calculation/6304/5 "2022-03-21T23:50:15Z")
Ok i’ll tell you more detail I’m writing Log in contract. Are there any best practice for this? As i know log only accept log for 1 bytes. So i have to put all parametters in a single bytes. Thats why i asked this question. For example with the question i ask, i want to log the value 00000000000000040000000000000007 To express the 2 value 4 and 7. So the log-reader can understand it is 2 params, each 64 bit. So i think the question here should be how to express 2 uint64 in a single bytes? ---
**Author:** ![hungpq](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@hungpq](https://forum.algorand.co/u/hungpq)\ **Post date:** [March 22, 2022, 7:06am UTC](https://forum.algorand.co/t/complex-math-calculation/6304/6 "2022-03-22T07:06:02Z")
And speaking of log, i read this in the docs ([Opcodes - Algorand Developer Portal](https://developer.algorand.org/docs/get-details/dapps/avm/teal/opcodes/#log)) that have the limit MaxLogCalls params. Could you tell me more about this limit, is that max number of log in a transaction. or an application only can log MaxLogCalls time, then it can not emit log anymore? ---
**Author:** ![Ben](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.algorand.co/ben/32/1979_2.png) [@Ben](https://forum.algorand.co/u/Ben)\ **Post date:** [March 22, 2022, 10:53am UTC](https://forum.algorand.co/t/complex-math-calculation/6304/7 "2022-03-22T10:53:30Z")
Hung, The limits for log are detailed here: > **[Algorand parameter tables - Algorand Developer Portal](https://developer.algorand.org/docs/get-details/parameter_tables/?from_query=parameters#smart-contract-constraints)** > > Algorand Developer Docs, SDKs, REST APIs, CLI tools, ecosystem projects, metrics dashboard and sample code, how-tos, and news from the Algorand developer community Up to 32 times, up to 1024 bytes ---
**Author:** ![hungpq](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@hungpq](https://forum.algorand.co/u/hungpq)\ **Post date:** [March 22, 2022, 11:09am UTC](https://forum.algorand.co/t/complex-math-calculation/6304/8 "2022-03-22T11:09:30Z")
Thanks Ben for your answer. it help me a lot what i want to ask here is Up to 32 times, up to 1024 bytes in a single transaction/1 application call. or it is a limit forever in an application. it can log up to 32 times for entire life cycle of its. no matter in how many transactions call to its application? ---
**Author:** ![Ben](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.algorand.co/ben/32/1979_2.png) [@Ben](https://forum.algorand.co/u/Ben)\ **Post date:** [March 22, 2022, 1:56pm UTC](https://forum.algorand.co/t/complex-math-calculation/6304/9 "2022-03-22T13:56:53Z")
Its a per application call limit. Ben ---
**Author:** ![FrankS](https://avatars.discourse-cdn.com/v4/letter/f/74df32/32.png) [@FrankS](https://forum.algorand.co/u/FrankS)\ **Post date:** [March 22, 2022, 9:20pm UTC](https://forum.algorand.co/t/complex-math-calculation/6304/10 "2022-03-22T21:20:00Z")
Itob and concat. If by bytesadd you mean the bigint byte array numbers then exp will need b× and a loop