Difference operator

There's this little symbol called the difference operator, which looks like a triangle or a little mountain. It helps us do math with numbers and see how much they change or are different from each other.

Let's say you have a fancy toy car collection and you want to see how much the value of your collection changed from last year to this year. You can use the difference operator to find out by subtracting the value of the collection from last year from the value of the collection this year. The answer you get is how much the value of your collection changed or increased.

It's kind of like counting how many more cookies you have now than you did yesterday. You can count the cookies you have now and subtract the amount you had yesterday to get the answer. The difference operator just makes it easier to do this kind of math with bigger numbers or more complicated equations in things like calculus or physics.