Confused by order of operations
 Confused by order of operations ward Unladen Swallow Posts: 4 Threads: 2 Joined: Jan 2019 Reputation: Jan-22-2019, 08:08 PM I'm doing a seminar to learn Python, and I've been asked to predict the result of this code:`print ( 5*2 - 3+4/2 )`The lesson explained the order of operations as Parentheses, Exponents, Multiplication and Division, Addition and Subtraction. So I first multiplied 5 by 2 to get 10. Then I divided 4 by 2 to get 2. So now it's 10 - 3 + 2. Then I added 3 to 2 to get 5. Finally, I subtracted 5 from 10. So I predicted the result to be 5. But here's the result: ``Output:9.0``. What's wrong with my calculation? What order of operations could result in 9.0? (I'm using Python 3.) Reply ichabod801 Bunny Rabbit Posts: 4,229 Threads: 97 Joined: Sep 2016 Reputation: Jan-22-2019, 08:23 PM Addition and subtraction are at the same level (just like multiplication and division). Everything at the same level is done left to right, then move to the next level. So 10 - 3 first, then add 2 to that. Craig "Ichabod" O'Brien - xenomind.com I wish you happiness. Recommended Tutorials: BBCode, functions, classes, text adventures Reply Larz60+ aetate et sapientia Posts: 11,549 Threads: 445 Joined: Sep 2016 Reputation: Jan-22-2019, 08:25 PM FYI Official doc: https://en.wikibooks.org/wiki/Python_Pro...Operations Reply ward Unladen Swallow Posts: 4 Threads: 2 Joined: Jan 2019 Reputation: Jan-22-2019, 08:40 PM Thanks for your answer, ichabod801. If I were to edit the tutorial, I'd have said "Parentheses, Exponents, Multiplication/Division, Addition/Subtraction" to convey that the latter sequences are not strict; they depend on whichever operator is encountered first, from left to right. And thanks for the link, Larz60+; it looks like a good resource. In my defense, I learned about order of operations in high school 55 years ago, so it's a little foggy Reply Larz60+ aetate et sapientia Posts: 11,549 Threads: 445 Joined: Sep 2016 Reputation: Jan-22-2019, 08:53 PM I think we graduated high school same year, 1964 for me! Reply

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