Bar graph: A graph that uses bars to show data. The taller the bar, the greater the amount.
Note: Bar graphs help us compare different groups of data easily by looking at the height of each bar.
- Look at the bar graph and find the bars for apples and bananas
- Read the number at the top of each bar
- Compare the numbers: the higher number means more children liked that fruit
The apple bar goes up to 8, so 8 children like apples
The banana bar goes up to 6, so 6 children like bananas
8 is more than 6, so more children like apples than bananas
More children liked apples (8) than bananas (6)
• Reading bars: Look at the height of each bar to find the number
• Comparison: Compare numbers to see which is greater
• Interpretation: Higher bar means more children chose that option
• Practice Tip: Count the units on the side of the graph to read exact numbers
- Comparing heights of different bars to find the most popular choice
- Using bar graphs to compare quantities of different items
- Reading numbers from the vertical scale of the bar graph
- Always look at the numbers on the side of the bar graph
- The tallest bar shows the most popular choice
- Count up from the bottom to find the exact number
Q: How do I read a bar graph?
A: Look at the height of each bar and match it to the numbers on the side. The taller the bar, the more of that item.
Q: What if two bars are the same height?
A: Then those two options have the same number of votes or amounts.
Picture graph: A graph that uses pictures to represent data. Each picture stands for one or more items.
Note: Picture graphs are fun and easy to read because we can count the actual pictures.
- Count the number of dog pictures
- Count the number of cat pictures
- Subtract to find how many more dogs there are than cats
There are 8 dog pictures, so there are 8 dogs
There are 5 cat pictures, so there are 5 cats
8 - 5 = 3, so there are 3 more dogs than cats
There are 3 more dogs than cats
• Counting pictures: Each picture represents one item (unless stated otherwise)
• Subtraction: To find "how many more", subtract the smaller number from the larger number
• Comparison: Look at the total number of each type of picture
• Practice Tip: Circle or mark each picture as you count to avoid mistakes
- Counting stars in a picture graph to see which student earned the most
- Comparing apples and oranges using picture graphs
- Reading picture graphs where each picture might represent more than one item
- Always check if each picture represents 1 or more items
- Count slowly and carefully to avoid missing pictures
- Use your finger to point to each picture as you count
Q: What if each picture represents more than one item?
A: Then multiply the number of pictures by the value each picture represents.
Q: How do I find how many more or fewer?
A: Subtract the smaller number from the larger number.
Tally chart: A table that uses tally marks to record data. Each group of 5 tally marks is shown as 4 vertical lines with a diagonal line across them.
Note: Tally charts help us count things quickly and accurately.
- Find the row for blue in the tally chart
- Count the groups of 5 (each cross with 4 lines)
- Count any extra single lines
- Add them together to get the total
Blue: |||| |||| |
There are 2 groups of 5 tally marks (each group of 4 lines with a cross)
There is 1 extra line after the groups
2 groups of 5 = 10, plus 1 extra = 11 total
11 children chose blue as their favorite color
• Tally marks: 4 vertical lines with a diagonal line across = 5
• Counting: Each group of 5, plus any extra lines
• Adding: Add groups of 5 to extra lines to get total
• Practice Tip: Count groups of 5 first, then add single lines
- Reading tally charts for favorite snacks
- Counting attendance using tally marks
- Recording survey results with tally charts
- Each group of 5 tally marks = 5 items
- Count groups of 5 first, then add single lines
- The diagonal line goes across 4 vertical lines to make 5
Q: How do I count tally marks?
A: Count each group of 5 (4 lines with a cross) as 5, then add any extra lines.
Q: Why do we use tally marks?
A: They make counting large numbers easier and help us keep track of our count.
Data comparison: Looking at two or more sets of data to see which has more, less, or equal amounts.
Note: We can compare numbers directly to see which is greater or lesser.
- Look at the first number (7 apples)
- Look at the second number (9 oranges)
- Compare the numbers: 7 < 9, so 9 is more than 7
- State which group has more
We have 7 apples and 9 oranges
7 is less than 9, so 9 is more than 7
Since 9 > 7, oranges have more items
Oranges have more items (9) than apples (7)
• Number comparison: Use symbols > (greater than) and < (less than)
• Visual aid: Draw or imagine the items to help compare
• Conclusion: State which group has more based on the comparison
• Practice Tip: Remember: the open mouth of the symbol faces the larger number
- Comparing 12 books to 8 toys: 12 > 8, so more books
- Comparing 5 pencils to 5 markers: 5 = 5, so equal amounts
- Comparing 3 cats to 6 dogs: 3 < 6, so more dogs
- Draw dots or lines to represent each item if needed
- Remember: > means "greater than" and < means "less than"
- Count each group carefully before comparing
Q: How do I know which number is bigger?
A: Think about which number comes later when counting: 7, 8, 9. Since 9 comes after 7, 9 is bigger.
Q: What if the numbers are the same?
A: Then both groups have equal amounts. We use the = symbol.
Difference: To find how many more or less, subtract the smaller number from the larger number.
Note: Finding the difference helps us understand the gap between two amounts.
- Identify the larger number (red cars: 12)
- Identify the smaller number (blue cars: 8)
- Subtract the smaller number from the larger number (12 - 8)
- State the difference
Red cars: 12, Blue cars: 8
12 is larger than 8
12 - 8 = 4
There are 4 more red cars than blue cars
There are 4 more red cars than blue cars
• Subtraction: To find "how many more", subtract the smaller from the larger
• Comparison: Identify which number is larger and which is smaller
• Verification: Check that the difference makes sense (8 + 4 = 12)
• Practice Tip: Use manipulatives or draw to visualize the difference
- 15 birds vs 9 butterflies: 15 - 9 = 6 more birds
- 20 candies vs 13 cookies: 20 - 13 = 7 more candies
- 7 flowers vs 4 trees: 7 - 4 = 3 more flowers
- To find "how many more", always subtract the smaller number from the larger
- You can also think: "What do I add to the smaller number to get the larger?"
- Check your answer by adding the difference back to the smaller number
Q: What if I subtract the wrong way?
A: You'll get a negative number, which doesn't make sense for counting objects. Always subtract the smaller from the larger.
Q: Can I use addition to check my answer?
A: Yes! Add the difference to the smaller number to see if you get the larger number.