## arithmetic errors

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* defaults:
    * solidity < 0.8: integers in overflow / underflow without any errors.
    * solidity >= 0.8: default behaviour of for overflow / underflow is to throw an error.
* use **[SafeMath](https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/math/SafeMath.sol)** to prevent arithmetic overflow and underflow.

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### chapters

<br>

* **[overflow](overflow)**