To count is to arrive at a number for a group of things or people, but the word "count" is also used when describing something that is important or something that really matters.
His opinion doesn’t count. (It’s not important in this situation. / It doesn’t matter.)
The decisions she makes really count.Everyone in the company is affected by what she decides.
Elections count. Go vote!
If you add the preposition "on" to "count," you get "count on" which means depend on or rely on:
You can’t count on him to come to class on time. He’s always late.
Can I count on you to help me this weekend?
I’m counting on you.
He counts on his wife for her support.
The next set of examples shows how the word "count" might be used when determining a number.
The little girl can count up to twenty.
Did you count all of the students in the classroom?
An odometer counts the number of miles that a car has traveled.
She met so many interesting people at the event she can’t count them all.
The word can also be used as a noun when talking about an amount:
What’s the count? (….during a baseball game when asking about balls and strikes.)
We have to do another count. (When talking inventory at a store.)
A recent count of city residents shows that the population has increased by ten percent.
By my count, there are a few people missing from our group.
Some people use an adding machine to count things.
Some people use an adding machine to count things.