Q1. Siti spends $60 total on books. The book slice is 90 degrees. How much did she spend?
✔ Calculate value per degree: 60 divided by 360 is 1/6. Multiply by 90 degrees to get 15 dollars.
Q2. Ravi's savings pie chart shows Food at 120 degrees and Transport at 90 degrees. What is the Savings angle?
✔ Subtract known angles from total: 360 minus 120 minus 90 equals 150 degrees.
Q3. Wei Ming pays $2.40 for MRT fare. The angle is 60 degrees. What is his total budget?
✔ Find value of one degree: 2.40 divided by 60 is 0.04. Multiply by 360 degrees to get 14.40 dollars.
Show transcript
[Slide 1] Understanding Pie Charts
Hello class! Today we explore pie charts using Singapore contexts. Imagine dividing your pocket money into slices like a pizza. Each slice angle tells us the value share.
[Slide 2] The Bar Model Method
We use the bar model to visualise the relationship. The total circle is three hundred sixty degrees, just like our full bar. This helps us find missing values easily.
[Slide 3] Mei Ling at Hawker Centre
Let us solve a problem about Mei Ling at Tampines Hawker Centre. She has one hundred twenty dollars to spend on food and transport. The pie chart shows the angles for each category.
[Slide 4] Calculating Food Cost
First, find the value of one degree using the bar model. Then multiply by one hundred fifty degrees for food. Mei Ling spends fifty dollars on her delicious meal.
[Slide 5] Common Mistakes to Avoid
Many students forget that the whole circle must be three hundred sixty degrees. Always check your angles sum up before calculating money. This prevents silly errors in exams.
[Slide 6] Key Takeaways for PSLE
Remember, the angle size matches the value proportion. Use bar models to keep your thinking organised during tests. You are now ready for PSLE pie chart questions!