uint256 input in RemixIDE - solidity

Question

I'm trying to learn developing my first smart contract in order to use flash loans on aave. I have a problem regarding the amount input for the transaction.
I've a function asking for the amount of token I need and the type is uint256. When I type 10 I only receive 0.0000000000000001 by the flash loan. Why? Maybe it's a stupid question but I'm not understanding what's wrong.
// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.6.12;
import { FlashLoanReceiverBase } from "./FlashLoanReceiverBase.sol";
import { ILendingPool, ILendingPoolAddressesProvider, IERC20 } from "./Interfaces.sol";
import { SafeMath } from "./Libraries.sol";
import "./Ownable.sol";
/*
* A contract that executes the following logic in a single atomic transaction:
*
*
*/
contract BatchFlashDemo is FlashLoanReceiverBase, Ownable {
ILendingPoolAddressesProvider provider;
using SafeMath for uint256;
uint256 flashDaiAmt0;
address lendingPoolAddr;
// mumbai reserve asset addresses
address mumbaiDai = 0x001B3B4d0F3714Ca98ba10F6042DaEbF0B1B7b6F;
// intantiate lending pool addresses provider and get lending pool address
constructor(ILendingPoolAddressesProvider _addressProvider) FlashLoanReceiverBase(_addressProvider) public {
provider = _addressProvider;
lendingPoolAddr = provider.getLendingPool();
}
/**
This function is called after your contract has received the flash loaned amount
*/
function executeOperation(
address[] calldata assets,
uint256[] calldata amounts,
uint256[] calldata premiums,
address initiator,
bytes calldata params
)
external
override
returns (bool)
{
/*
*
*
*/
// Approve the LendingPool contract allowance to *pull* the owed amount
// i.e. AAVE V2's way of repaying the flash loan
for (uint i = 0; i < assets.length; i++) {
uint amountOwing = amounts[i].add(premiums[i]);
IERC20(assets[i]).approve(address(_lendingPool), amountOwing);
}
return true;
}
/*
* This function is manually called to commence the flash loans sequence
*/
function executeFlashLoans(uint256 _flashDaiAmt0) public onlyOwner {
address receiverAddress = address(this);
// the various assets to be flashed
address[] memory assets = new address[](1);
assets[0] = mumbaiDai;
// the amount to be flashed for each asset
uint256[] memory amounts = new uint256[](1);
amounts[0] = _flashDaiAmt0;
flashDaiAmt0 = _flashDaiAmt0;
// 0 = no debt, 1 = stable, 2 = variable
uint256[] memory modes = new uint256[](1);
modes[0] = 0;
address onBehalfOf = address(this);
bytes memory params = "";
uint16 referralCode = 0;
_lendingPool.flashLoan(
receiverAddress,
assets,
amounts,
modes,
onBehalfOf,
params,
referralCode
);
}
/*
* Rugpull all ERC20 tokens from the contract
*/
function rugPull() public payable onlyOwner {
// withdraw all ETH
msg.sender.call{ value: address(this).balance }("");
// withdraw all x ERC20 tokens
IERC20(mumbaiDai).transfer(msg.sender, IERC20(mumbaiDai).balanceOf(address(this)));
}
}
I'm deploying passing this address as parameter:
0x178113104fEcbcD7fF8669a0150721e231F0FD4B
it is the Lending Pool Addresses Provider contract taken from here: https://docs.aave.com/developers/v/2.0/deployed-contracts/matic-polygon-market.
When I try asking for more than 1000tokens I get the error. Hope this helps to reproduce.

Answer 1

EVM doesn't support decimal numbers. So a common approach is to declare a number of decimals in the contract, and then include them with the stored values.
Example:
When a contract uses 2 decimals, value of 1 is stored as 100.
Aave protocol works with ERC20 tokens, where the standard defines a function named decimals() to return a number of decimal places.