Hey buddy, have you ever played a game where you have to keep adding points every time you do something good? That's like a running total!
A running total is when you keep adding up numbers as you go along. Let's say you're counting how many pieces of candy you have. You start with one candy, and then you get another one. Now you have two candies! Then you get three more candies, so you count them all up: one, two, three... now you have five candies in total!
See how you're keeping track of all the candies you get, and you're adding them up every time you get more? That's a running total!
It's useful in lots of different situations, like keeping track of how much money you've spent at the grocery store, or how many laps you've run around the playground. As you keep doing the thing you're counting, you just add up all the things you've done so far, and that's your running total. Pretty cool, huh?