I was helping to teach math centers in my 1st grader's classroom last week.
One of the lessons was to count up from 7 to 97 in 10s, with or without a calculator.

I was showing one student how to use the calculator to do this, whilst teaching the concept of counting in 10s.

7 + 10 = 17 + 10 = 27 + 10 = 37 etc.

I got to about 67, when a little girl at the same table put up her hand.
She said, "You know, it's much easier if you just keep hitting the = button!"

I suppressed my grin, and thanked her for the advice.

Now, I did actually know this, but I was also trying to teach the concept of counting by 10s .

I left the classroom that day smiling at my lesson in technology.

When I told my wife the story that night, she replied,

"You can do that?"