Multiply 1,023 and 102 first because you always have to do your problems left to right in math. Your equation should now look like 104,346 + 112 - 5. Calculate the sum of the positive numbers by adding 104, 346 + 112. Your equation should now be 104,458 - 5. Then lastly, you subtract the numbers 104,458 and 5, and you should get 104, 453 as your answer.