Maths in function not working?

Question

so I have a function getPriceReserveBuySUForEth that is returning the incorrect value and I'm not sure why :| I guess what the function does and the purpose doesn't really matter so I won't waste the space here The function:

function getPriceReserveBuySUForEth(uint256 _value) public view returns (uint256) {
    require(getAvailableReserveUSD(0) > 0);                     // Need to have some reserve available in order to buy SU back

    uint256 maxReserveAvailable = address(this).balance * getEthPrice() * percentDropBeforeBonds / 100;
    uint256 m = 2 * maxReserveAvailable / ((maxReservePriceDeviationInCents * 10**24)**2);
    uint256 amountReserveUsedUp = maxReserveAvailable - uint(getAvailableReserveUSD(0));
    uint256 averageTradePrice = sqrt(2 * (amountReserveUsedUp + _value) / m);
    uint256 tempVal = 10**26 - averageTradePrice;
    return tempVal;
}

When using 0 as the input, it sgould return 10^26, however it returns 0.

averageTradePrice should = 0. Therefore 10^26 - 0 should = 10^26. I tested this with a function y:

function y(uint256 _value) public view returns (uint256) {
    return 10**26 - 0;
} // I know _value doesn't do anything here - I was just lazy in copy/pasting

This correctly returns 10^26. Also I created a function x to test that averageTradePrice does indeed = 0:

function x(uint256 _value) public view returns (uint256) {
    require(getAvailableReserveUSD(0) > 0);                     // Need to have some reserve available in order to buy SU back

    uint256 maxReserveAvailable = address(this).balance * getEthPrice() * percentDropBeforeBonds / 100;
    uint256 m = 2 * maxReserveAvailable / ((maxReservePriceDeviationInCents * 10**24)**2);
    uint256 amountReserveUsedUp = maxReserveAvailable - uint(getAvailableReserveUSD(0));
    return sqrt(2 * (amountReserveUsedUp + _value) / m);
}

This is the exact same function as getPriceReserveBuySUForEth, except it returns the value for averageTradePrice instead of 20^26 - averageTradePrice. x(0) does indeed return 0 like it should. So why does getPriceReserveBuySUForEth return 0 when it should return 10^26??

Answer 1

Turns out the issue was that m was a number much less than 1 (close to 0), so solidity interpreted it as 0, which messed up the rest of the calculation. Not having floats is sooooo frustrating!