Tally Charts & Frequency Tables (Cambridge International IGCSE Maths)

Tally charts & frequency tables

What is a tally chart?

• Tally charts are a quick way to count data

• Each time you count an item, draw a vertical line

  • Do this the first four times
  • The fifth time, draw a diagonal line through the four vertical lines $\cancel{\vert \vert \vert \vert}$
  • Continue counting in sets of five

• For example

  • Counting different coloured flowers in the garden

What is a frequency table?

• A frequency table counts how many times an item appears

• Tally charts can be converted into frequency tables

  • Find the totals

    • Count up in 5's then add any extras
    • $\cancel{\vert \vert \vert \vert} \cancel{\vert \vert \vert \vert} \vert \vert$means 5 + 5 + 2 = 12

• The tally chart above gives the following frequency table:

Worked Example Susie asks pupils in her class to select their favourite type of pet.

Write the results in a frequency table.

Dog	Cat	Dog	Dog	Dog
Rabbit	Dog	Rabbit	Cat	Cat
Cat	Dog	Dog	Rabbit	Dog
Cat	Cat	Dog	Dog	Dog

Answer:

It helps to use a tally chart initially

Type of pet	Tally
Dog	* *$\cancel{\vert \vert \vert \vert} \vert \cancel{\vert \vert \vert} \vert$
Cat	* *$\cancel{\vert \vert \vert \vert} \vert$
Rabbit	* *$\vert \vert \vert$

Then write the tally chart as a frequency table

Final answer: Type of pet	Final answer: Frequency
Final answer: Dog	Final answer: 11
Final answer: Cat	Final answer: 6
Final answer: Rabbit	Final answer: 3