Back To Course

Student Resources13 chapters | 252 lessons

Instructor:
*Jessica Keys*

Why not try a little mental exercise with this selection of eight fun math puzzles? All you need is your brain and a sense of logic. But beware, some of these are tricky! (If you get stumped, don't worry! This article includes all the answers at the end.)

The Seashell Hotel set up a lovely buffet for Mother's Day. Among other things, the chef has whipped up a marvelous chocolate cherry cheesecake. Out on the patio, two mothers and two daughters are dining on *three* pieces of cheesecake, with *one piece per person*. How is this possible?

Can you replace the letters in this equation with numbers to make a correct mathematical expression?

(R+O+B+O+T)³ = ROBOT

Here's a number: 8549176320. It looks like a random jumbly number, but it's actually quite special. Can you figure out why?

Hard to believe, but it's possible to get every integer between 0 and 8 by using four 4's (no more, no less, but decimal points are allowed) and the common math operators: addition, subtraction, multiplication, division, square root and the factorial (e.g. 4! = 1*2*3*4 = 24).

How many can you get?

Did you know? In math, there is a symbol you can stick between the numbers 7 and 8 that'll give you a number larger than 7, but smaller than 8. What is it?

'Decimals? Bah! That may be how math works on your Earth, but here on Mars everyone knows one half of five is three exactly,' grumbled Jim the Martian, as if he had just heard the most ridiculous thing in his life.

If one half of five is three on Mars, and assuming this strange proportion is the rule, what is one third of ten?

Doctor Crumbs has got her manufacturing business down to a science. Now *one and a half* of her lawn chair making-machines can produce exactly *one and a half* lawn chairs every *one and a half* hours. Unfortunately, this silly math has confounded her potential investors. Can you help her figure out how many lawn chairs *one* machine can produce in *one* hour?

Can you add eight 8s to get the number 1000?

If you're really enjoying challenging your brain and building your math skills, give one of Study.com's online math courses a try. These courses cover all skill and age levels, from Math for Kids to High School Algebra and Trigonometry, to even more advanced college-level topics like Calculus and abstract Contemporary Math.

Accessible any time and completely self-paced, Study.com's courses are designed with your schedule in mind. Also, each course lesson has a quiz at the end for step-by-step testing!

Here are the answers to all the puzzles. Don't look unless you're really stumped!

**Puzzle #1**: Out of the two mothers, one is actually a grandmother. This means one of the mothers is both a mother *and* a daughter. So technically, the table seats two mothers (the grandmother and the mother) and two daughters (the mother and her daughter).

**Puzzle #2**: If R = 1, O = 7, B = 5, O=7, T = 6, then (1+7+5+7+6)³ = (26)³ = 17576.

**Puzzle #3**: 8549176320 is all the single digits (0-9) rearranged in alphabetical order: 'Eight, Five, Four, Nine, One…'

**Puzzle #4**: Some solutions for 0 to 8 are:

(4+4) - (4+4) = 0 | (4+4) / (4+4) = 1 | (4/4) + (4/4) = 2 |

((4+4) + 4)/4 = 3 | 4(4-4) + 4 = 4 | ((4*4)+4)/4 = 5 |

4(.4) + 4.4 = 6 | (44/4) - 4 = 7 | 4 + (4.4 - .4) = 8 |

Of course, you don't have to stop at just 8! For a challenge, see how far you can go using these rules.

**Puzzle #5**: A decimal point! 7.8 is larger than 7 and smaller than 8. Try this one out on your friends if you really want to annoy them. (No more trick questions, promise!)

**Puzzle #6**: We know that according to Martian rules, 1/2 * 5 = 3 (Here on Earth, the real answer is 2.5). We want to know what 1/3 * 10 would be using the same wonky proportions.

- Try setting up the problem like so: 1/2 * 5 = 3.
- But we want to know about thirds. So multiply both sides of the equation by 1/3. You will end up with 1/6 * 5 = 1. Getting there!
- Turn that 1/6 into 1/3 by multiplying both sides by two and you will end up with 1/3 * 5 = 2. So, one third of five is two…
- Now all you have to do is double the whole thing (multiply both sides by two again) to figure out what one third of ten would be. (It is, of course, four.)

**Puzzle #7**: All you have to do is work out the rate per hour (r) using this formula: x Machines * y Hours * (r) = z Lawn Chairs.

The starting expression is 1½ * 1½ * (r) = 1½. Isolate *r* by dividing out the 1½ * 1½, where it will then become the denominator on the other side:

- r = 1½ / (1½ * 1½)

You can simplify this fraction by canceling out the 1½ in the numerator with a 1½ in the denominator. This leaves you with:

- r = 1 / 1½, or r = 1 / (3/2), which becomes r = 2/3.

So, one lawn chair machine can make 2/3rds of one lawn chair in one hour. How silly!

**Puzzle #8**: To get 1000 by adding eight 8s, try 888 + 88 + 8 + 8 + 8. It helps if you remember that 8 x 5 is 40, a number that ends in zero. Therefore, dividing the eight 8s into five portions will get you a number that ends in zero.

Did you know… We have over 160 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

You are viewing lesson
Lesson
22 in chapter 9 of the course:

Back To Course

Student Resources13 chapters | 252 lessons

- Free Online High School Math Courses
- Math Fraction Games
- Multiplication Math Games
- Subtraction Math Games
- 3rd Grade Math Projects
- 8th Grade Math Games
- Addition Math Games
- Algebra Math Games
- Division Math Games
- Fun Math Games for 1st Grade
- Fun Math Games for 2nd Grade
- Fun Math Games for 3rd Grade
- Fun Math Games for 4th Grade
- Fun Math Games for 5th Grade
- Fun Math Games for 6th Grade
- Fun Math Games for Kids
- Fun Math Games for Middle School
- Fun Math Games for the Classroom
- Geometry Math Games
- Halloween Math Games
- High School Math Games
- Cool Math Puzzles
- What is the Math Olympiad Contest?
- Mental Math Games
- Pi Day Project Ideas
- Math Poster Ideas
- How to Improve Math Skills
- How to Pass Calculus
- How to Pass Precalculus
- How to Pass College Algebra
- How to Pass Algebra 2
- How to Pass Algebra 1
- How to Pass Intermediate Algebra
- How to Pass a Math Test
- How to Pass Math
- How to Pass the COMPASS Math Test
- How to Pass Trigonometry
- How to Pass Statistics
- What is Saxon Math?
- Go to Resources for Learning Math

Courses: **{{pfc.courses.length}}**

Business 101: Principles of Management

View Lessons (129)

Introduction to Management: Help and Review

View Lessons (312)

Information Systems: Help and Review

View Lessons (387)

Biology 105: Anatomy & Physiology

View Lessons (179)

Sociology 101: Intro to Sociology

View Lessons (126)

Psychology 105: Research Methods in Psychology

View Lessons (137)

Biology 101: Intro to Biology

View Lessons (151)

Chemistry 101: General Chemistry

View Lessons (132)

Earth Science 101: Earth Science

View Lessons (168)

Introduction to Business: Homework Help Resource

View Lessons (508)

Human Anatomy & Physiology: Help and Review

View Lessons (736)

Intro to Business: Help and Review

View Lessons (518)

Business 107: Organizational Behavior

View Lessons (142)

Psychology 102: Educational Psychology

View Lessons (123)

Principles of Marketing: Help and Review

View Lessons (253)

Economics 102: Macroeconomics

View Lessons (137)

High School Biology: Help and Review

View Lessons (570)

Intro to Psychology: Help and Review

View Lessons (342)

College Biology: Help and Review

View Lessons (433)

Business 104: Information Systems and Computer Applications

View Lessons (111)

Please revise your filter set to expand your results

Browse by subject