uma/packages/core/contracts/common/interfaces/IERC20Standard.sol

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

/**
 * @title ERC20 interface that includes the decimals read only method.
 */
interface IERC20Standard is IERC20 {
    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should be displayed to a user as `5,05`
     * (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between Ether and Wei. This is the value
     * {ERC20} uses, unless {_setupDecimals} is called.
     *
     * NOTE: This information is only used for _display_ purposes: it in no way affects any of the arithmetic
     * of the contract, including {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() external view returns (uint8);
}