Basics
π = pi
π = approximately 3.141592654 = approximately 3.14
π = ratio of a circle’s circumference to its diameter
π is primarily a multiplier.
When π is immediately adjacent to a number, letter or parenthesis, an invisible multiplication sign is in force.
5π = 5 × π
π5 = π × 5
rπ = r × π
πr = π × r
π(5) = π × 5
5(π) = 5 × π
π(r) = π × r
r(π) = r × π
When asked to convert an answer from π to decimal form, use the toggle button .
is the π command.
Question
What is 5 × π?
Answer
5π
Input  Display  Comment 
blinker  clears screen  
5 ×  5*π  
5π  Answer  
π 
Question
What is π × 5?
Answer
5π
Input  Display  Comment 
blinker  clears screen  
× 5  π*5  
5π  Answer  
π 
Question
In decimal form, what is 5 × π?
Answer
15.70796327
Answer Process
See Toggle.
5π ⇔ 15.70796327
Input  Display  Comment 
blinker  clears screen  
5 ×  5*π  
5π  
15.70796327  Answer (Toggle) 

π 
Question
With reference to the question above, round your answer to the nearest hundredth.
Answer
15.71
Answer Process
See Rounding.
15.70796327 → 15.71
Practice – Questions
1. What is 2 × π?
2. What is π × 2?
3. In decimal form, what is 2 × π?
4. With reference to Question 3, round your answer to the nearest hundredth.
5. With reference to Question 3, round your answer to the nearest tenth.
6. What is 8 × π?
7. What is π × 8?
8. In decimal form, what is 8 × π?
9. With reference to Question 8, round your answer to the nearest hundredth.
10. With reference to Question 8, round your answer to the nearest tenth.
Practice – Answers
1. 2π
2. 2π
3. 6.283185307
4. 6.28
5. 6.3
6. 8π
7. 8π
8. 25.13274123
9. 25.13
10. 25.1