11+ exam: Maths – pie charts | Bond 11+

TL;DR

This content explains how to find angles in a pie chart and calculate the number of children who prefer a specific ice cream flavor using fractions.

Transcript

data is often represented in pie charts and being able to find angles and relate those angles back to the data is an important mathematical skill in the 11 plus so here we've got a pie chart showing the results of a survey of 240 children and their responses about which ice cream flavor they like the best so our question is how many children said r... Read More

Key Insights

• 🥧 Understanding angles in pie charts is crucial for accurately interpreting and analyzing data.
• 🥧 The diameter of a pie chart represents a 180° angle.
• 🔺 Subtracting known angles from the total angle helps find the angle for a specific section.
• 👻 Converting the angle into a fraction allows us to determine the proportion of the total population.
• ❓ Canceling down fractions simplifies calculations and provides a more manageable representation.
• 💛 The yellow section in the pie chart represents the raspberry flavor preference.
• 🟡 The angle for the yellow section is 30°, making raspberry 1/12th of the circle.

Questions & Answers

Q: Why is it important to be able to find angles in a pie chart?

Finding angles in a pie chart allows us to accurately determine the proportion of each category in relation to the whole, making data interpretation more precise.

Q: How can we find the angle for a specific section in a pie chart?

By using the known angles of other sections (e.g., a 90° angle in the red section), we can subtract those angles from the total angle (in this case, 180°) to find the angle for the desired section (yellow/raspberry).

Q: How do we relate the angle to the number of children who like raspberry ice cream?

The angle is converted into a fraction (30° becomes 1/12 of the circle) and then used to calculate the fraction of the total number of children (240) who prefer raspberry by multiplying it with 240.

Q: What is the final calculated number of children who like raspberry ice cream?

Using the fraction 1/12 and multiplying it by 240, we find that 20 children prefer raspberry ice cream.

Summary & Key Takeaways

• The content discusses the importance of understanding angles in pie charts for interpreting data.

• A survey of 240 children's ice cream preferences is represented in a pie chart.

• The content explains how to find the angle for a specific flavor (raspberry) and then convert it into a fraction to determine the number of children who like that flavor.