Adding it up is an ongoing guttmacher institute project that estimates the need for impact of and costs associated with providing essential sexual and reproductive health services. Add the two numbers and return it as a linked list you may assume the two numbers do not contain any leading zero except the number 0 itself follow up what if you cannot modify the input lists in other words reversing the lists is not allowed example input 7 2 4 3 5 6 4 output 7 8 0 7 accepted 173536 submissions 316240 contributor companies . Add the numbers 57 8 solution step 1 we line up the numbers vertically step 2 we add the digits in ones column 7 8 15 5 is written below ones column and 1 is carried over to tens column step 3 in tens column 5 1 6 we write 6 below tens column so the final sum is 65. This selection will show you how to add two numbers together it won t just give you the answer though the way your calculator would you will actually be shown how to add two numbers together step by step the long hand way this selection can be sort of fun too because it can show you how to add together very very large numbers that can have up to 30 digits each type in your