Statistics | 5th Grade Math

📊 Statistics Notes & Formulae (Grade 5)

1. Find the Mode

Mode is the number that appears most often in a data set.

\( \text{Mode} = \text{Value with the highest frequency} \)

2. Find the Mean (Average)

Mean is the sum of all numbers divided by how many numbers.

\( \text{Mean} = \frac{\text{Sum of all values}}{\text{Number of values}} \)

3. Find the Median

Median is the middle value when data is ordered from smallest to largest.

  • If odd number of terms: \( \text{Median} = \text{Middle Value} \)
  • If even number of terms: \( \text{Median} = \frac{\text{2 middle values sum}}{2} \)

4. Find the Range

Range shows the spread of the data.

\( \text{Range} = \text{Largest Value} - \text{Smallest Value} \)

5. Mean: Find the Missing Number

If the mean and all except one number are known, use:

\( (\text{Mean}) \times (\text{Total Numbers}) = \text{Sum of all values} \)
Missing number = Required sum – Known numbers sum

6. Median: Find the Missing Number

Arrange all numbers (including the unknown) in order.
Find which value must go in the blank for the median to be correct.

7. Range: Find the Missing Number

Set up:
\( \text{Range} = \text{Largest Value} – \text{Smallest Value} \)
To find missing, use range and other known numbers to solve for the unknown.

8-11. Interpretation from Charts & Graphs

Mode, Mean, Median, Range from a Chart/Graph:
- Identify relevant values in the visual representation.
- Apply formulas directly to the data extracted from the charts.

  • Mode: Most frequent value/bar/area
  • Mean: Add all shown values, divide by how many
  • Median: Middle value of sorted values
  • Range: Largest minus smallest value

✏️ Quick Tips

  • Always order data when searching for median.
  • Use tally marks for mode in large groups.
  • Mean is affected by outliers, median is not.