# Online math quiz - I have questions about 1 of them **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [October 19, 2020, 4:17pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329 "2020-10-19T16:17:03Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [October 19, 2020, 4:17pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/1 "2020-10-19T16:17:03Z")
This is a fairly easy quiz. Most of the questions test your understanding of the mathematical order of operations. Please Excuse My Dear Aunt Sally is a popular mnemonic. šŸ˜Š > **[Can YOU solve these basic maths questions?](https://www.dailymail.co.uk/femail/article-8852665/Tricky-quiz-test-numeracy-knowledge-4-people-10.html)** > > Michael Rodgers, who is known for creating difficult quizzes, shared the numeracy test on US-trivia website Playbuzz. This one is full of questions you need to answer without a calculator. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [October 19, 2020, 4:19pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/2 "2020-10-19T16:19:25Z")
I put my questions here to avoid spoilers in the OP. Question 15 seems incomplete. ā€œWhich is divisible by 7 without a remainder.ā€ Well, any multiple of 7 is divisible by 7 without a remainder. 14,21,28,35 etc. What am I missing here? Why does the answer key say 105? That is a multiple of 7 (7x15). Am I misunderstanding the question? I think of a remainder from long division. 15/7 is 2 with a remainder of 1. Or in fractions 2 1/7. I missed 2 questions. 13 and maybe 15. I didnā€™t want to find a pencil to figure out the square root of 4,096. I knew it was approx 200. Which is the square root of 4,000. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [October 19, 2020, 4:21pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/3 "2020-10-19T16:21:29Z")
Your article is unavailable to those of us who use adblockers. So youā€™ll need to post the entire pertinent part if you want more / better responses. As to your divisible by 7 question just above ā€¦ Youā€™re right; either you overlooked part of their question, or they forgot to publish part of it. _Any_ multiple of 7 is divisible by 7 without remainder. By the definition of multiplication & division. And since 7 is prime, _only_ multiples of 7 have this property. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [October 19, 2020, 4:25pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/4 "2020-10-19T16:25:16Z")
I canā€™t cut and paste the questions. Each one is a jpg. Hereā€™s the direct link for question 15. Or Software helpfully displays it. [![](https://i.dailymail.co.uk/1s/2020/10/18/16/34537766-8852665-image-m-93_1603035385115.jpg) ](https://i.dailymail.co.uk/1s/2020/10/18/16/34537766-8852665-image-m-93_1603035385115.jpg) Question 2 is interesting. I had to think a minute to solve it. [![](https://i.dailymail.co.uk/1s/2020/10/18/16/34537760-8852665-image-m-77_1603034893164.jpg) ](https://i.dailymail.co.uk/1s/2020/10/18/16/34537760-8852665-image-m-77_1603034893164.jpg) ---
**Author:** ![Hampshire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hampshire/32/4887_2.png) [@Hampshire](https://boards.straightdope.com/u/Hampshire)\ **Post date:** [October 19, 2020, 4:26pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/5 "2020-10-19T16:26:01Z")
Looks like it was originally a multiple choice question but they failed to include any choices. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [October 19, 2020, 4:27pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/6 "2020-10-19T16:27:44Z")
> [@aceplace57](#): > > I didnā€™t want to find a pencil to figure out the square root of 4,096. I knew it was approx 200. Which is the square root of 4,000. Not quite. 200 \* 200 = 40,000. The 2\*2 gives you a 4, then tack on all the zeros = 4 zeros. You only tacked on 3. Oops. Computer-ish people will instantly recognize that 4,096 is a power of 2. 2^12 to be exact. So its square root is 2^(12/2) = 2^6 = 64. For a sanity check 60\*60 = 36 with 2 zeros tacked on = 3600. So a number a little bigger than 60 will get us to 4000. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [October 19, 2020, 4:29pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/7 "2020-10-19T16:29:05Z")
Yeah! They stole this from somewhere, maybe someoneā€™s Kahoot, where they were all presented as multiple choice, and failed to notice that one of them required that format to make sense. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [October 19, 2020, 4:30pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/8 "2020-10-19T16:30:24Z")
I should have drank more coffee. šŸ¤” I knew better than dropping those zeros. It is a fun quiz. Nice diversion in the morning. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [October 19, 2020, 4:34pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/9 "2020-10-19T16:34:43Z")
I used to screw that one up all the time. I eventually just memorized in words: ā€œone hundred times one hundred is ten thousandā€. By remembering it in words, not figures, that makes it harder to fall for 1000 when you mean 10000. As to the 1/2 of 1/2 of 1/2 of 1/2 of 64, that again depends on noticing that 64 is a power of 2, and one half is also a power of 2 (2^-1) and that multiplication is commutative. So itā€™s: > 64 / 2 = ? / 2 = ? / 2 = ? / 2 = ? > or > 64 / 2 = 32. > 32 / 2 = 16. > 16 / 2 = 8. > 8 / 2 = 4. Viola! ---
**Author:** ![Snarky\_Kong](https://avatars.discourse-cdn.com/v4/letter/s/a183cd/32.png) [@Snarky\_Kong](https://boards.straightdope.com/u/Snarky_Kong)\ **Post date:** [October 19, 2020, 4:38pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/10 "2020-10-19T16:38:52Z")
Quiz treats implied multiplication as the same precedence as explicit multiplication, which is the cause of like 95% of viral math problems. Therefore I hate it. ---
**Author:** ![Snarky\_Kong](https://avatars.discourse-cdn.com/v4/letter/s/a183cd/32.png) [@Snarky\_Kong](https://boards.straightdope.com/u/Snarky_Kong)\ **Post date:** [October 19, 2020, 4:41pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/11 "2020-10-19T16:41:25Z")
There are choices included for all of them. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [October 19, 2020, 4:57pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/12 "2020-10-19T16:57:00Z")
I did the 1/2 of 1/2 of 1/2 of 1/2 of 64 by multiplying the fractions from left to right. 1/2 x 1/2 = 1/4 1/4 x 1/2 = 1/8 1/8 x 1/2 = 1/16 1/16 x 64 = 4 LSLGuy answer is more elegant ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [October 19, 2020, 5:08pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/13 "2020-10-19T17:08:59Z")
> [@Snarky\_Kong](#): > > There are choices included for all of them. Where? Iā€™m not seeing any choices. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [October 19, 2020, 5:10pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/14 "2020-10-19T17:10:59Z")
My job includes a lot of simple mental ballpark-ish math. You get good at recognizing how to rearrange things so the computation is easier. Tricks like: to divide by 5, instead divide by 10 by slicing off the last digit [with rounding if you care about that level of precision, just truncate if you donā€™t], then multiply by 2 by doubling. Thatā€™s also how I figure out 20% restaurant tips. etc. As to the 64 times 1/2 repeated 4 times I literally pointed my mouse at each 1/2 from right to left and mentally counted them down 32, 16, 8, 4 done. Took about 3 seconds to decide how to attack it and another 3 seconds to do. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [October 19, 2020, 5:23pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/15 "2020-10-19T17:23:05Z")
Online quizes love questions like this. But I would never code a equation like that. You have to think of the guy on call. Heā€™s up at Operations at 1 AM trying to fix an error. (maybe a report didnā€™t balance and the program ended with an error code). You have to write clean code. Use parentheses. Donā€™t rely entirely on the order of operations. [![](https://i.dailymail.co.uk/1s/2020/10/18/16/34537758-8852665-image-m-84_1603035048386.jpg) ](https://i.dailymail.co.uk/1s/2020/10/18/16/34537758-8852665-image-m-84_1603035048386.jpg) ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [October 19, 2020, 5:32pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/16 "2020-10-19T17:32:26Z")
Doh! It says so right in the text where it came from. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [October 19, 2020, 5:50pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/17 "2020-10-19T17:50:27Z")
šŸ˜… the DM made it harder by removing the multiple choices. We were working these old school. My math teachers rarely offered multiple choice. Ok. Now I understand why the last question seemed incomplete. ---
**Author:** ![Snarky\_Kong](https://avatars.discourse-cdn.com/v4/letter/s/a183cd/32.png) [@Snarky\_Kong](https://boards.straightdope.com/u/Snarky_Kong)\ **Post date:** [October 21, 2020, 3:40am UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/18 "2020-10-21T03:40:51Z")
Directly beneath each question. Did you guys click the link to the quiz? > **[Can You Solve This Basic IQ Test?](https://www.playbuzz.com/michaelrogers11/basic-iq-test)** > > This basic IQ test has been driving the internet wild for a few months. Only 4% of the people who took it got 10/15 of more correctly. How high can you score? Don't forget to let us know in the comments. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [October 21, 2020, 1:38pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/19 "2020-10-21T13:38:23Z")
The Daily Fail copied all the questions, without the answers, into their article and give the solutions at the bottom. Itā€™s not unreasonable to assume one can complete the challenge without going to the original source. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [October 21, 2020, 2:04pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/20 "2020-10-21T14:04:28Z")
I like how the OP has questions about 2 of the quiz items, but his title says he has questions about 1 of them. An old saw in developer land: There are 3 kinds of people: Those who can count, and those who canā€™t. šŸ˜‰ [Next page](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329.md?page=2)