To find the missing number that, when added to 157, equals 302, you would subtract 157 from 302. This calculation gives you 145. Therefore, 157 plus 145 equals 302.
Oh, dude, math time! So, like, if you add 157 plus what, you get 302. That's like, basic addition, man. So, the answer is 145. Easy peasy lemon squeezy.