Step by step
The question
Question: make a frequency table of 7, 8, 8, 9, 7, 8, 10, 8, 9, 8, 8 and 7.
The frequency of a number is how many times it comes.
1 List the values
We write each value once, smallest first: 7, 8, 9 and 10.
2 Tally
Careful!
Cross out each number as you count it.
Then none is missed, and none is counted twice.
The first number is 7.
We cross it out, and put one mark next to 7.
Next is 8: one mark next to 8.
And so on: one mark for each number.
The fifth mark goes across the other four.
That makes a group of 5, easy to count.
Every number is crossed out.
So every number has its mark.
3 Count
7 has 3 marks: f = 3.
8 has 6 marks: f = 6.
9 has 2 marks: f = 2.
10 has 1 mark: f = 1.
4 Check
Let's check.
We add the f column: 3 + 6 + 2 + 1 = 12.
There are 12 numbers in the list.
Every one is counted.
So it is right!
Let's look back.
First: list the values.
Then: tally.
Then: count.
Last: check.