Beginner dev, problem from ChainShot: Intro to Smart Contracts
Problem 2: Unsigned Integers
"Let's create three public state unsigned integers in our Contract: a, b, and sum. Define the variable a as an uint8 with an initial value between 0 and 255. If you declare the variable a as a uint8 you will actually be unable to store a value outside the range 0 to 255. If you try this directly in your program, you'll get a comrpile-time error! Define the variable b as an uint16 with a value of at least 256. The range for a uint16 is 0 to 65535. The variable sum should be a uint256 with the sum of the values stored in a and b. It's perfectly valid to add a uint8 and a uint16 and store them in a uint256. Mix it up! You can use uint256 or uint to declare the sum. The keyword uint is an alias for uint256 and it is often used!"
My answer so far, 2/3 validated. Need help on the the Sum part.
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
contract sum{
uint8 public a;
uint16 public b;
}