10 Magical Math Puzzles

Check out my post at We Are Teachers: 10 Magical Math Puzzles to make learning enchanting!

Shoe Math Magic

Multiply shoe size by 5 (must be a whole number, round up if you have to)
Add 50 
Multiply by 20 
Add 1013 
Subtract the year you were born 
First digit = shoe size 
Last 2 digits = age
via pinterest

Thaumatropes

Integrate art, math, science, as well as history by constructing a thaumatrope! Kids use their measuring skills and imagination to create a paper animation! "Thaumatropes are optical illusions that operate by switching between two images so rapidly that the images appear as one." - Molecular Expressions. Video by EllieBTECMedia

How to incorporate in your classroom:

Geometry - Have kids figure out the area of their circle or rectangle, as well as circumference and perimeter. You could also have them try making different shapes for their thaumatrope besides the basic circle, rectangle, or square.

Science - Create thaumatropes that go along with your unit (ex: weather: lightning and dark skies on one side and clear skies with puffy white clouds on the other). Also, states of matter: ice cube melting. They could also do a volcano erupting or a butterfly emerging from a chrysalis. Kids can get super creative with the project!

History - Check it out here!

Four different ways to construct a thaumatrope! All you need is cardstock, a hole puncher, glue/tape and one of the materials below. You can draw, use photos, or write messages to create your optical illusion!

Rubber Band (you need 2)

Wooden Skewer

Straw

String

Color UN-mixing

Awesome experiment from the Surfing Scientist! Kids investigate laminar flow: liquid flowing in parallel layers. They rotate a cylinder glass, watching colors mix and un-mix right before their eyes!

Art in Numbers: Multiplication Patterns

Practice your multiplication tables by creating grid paper designs from Sharynideas! Kids identify patterns in their multiplication tables. When they identify a repeating pattern, they create art! Check out the activity here! Also, visit NRich Math for a slightly different way to create designs from your times tables!

Fraction Color Spinner

Integrate math, art, and science by creating a colorful spinning toy! Kids trace a circle (at least 6 inch diameter) on poster board (or cardstock) and divide it into six equal parts. Then, they color it in, using any colors they'd like! Once it's colored, an adult punches two holes in the center of the circle. Kids measure out a 3 foot piece of string or yarn and lace it through their circle. Move the circle towards the center of the yarn (keep the one side of the string in a loop - don't pull the string all the way through). Next, tie a knot on the other side so it has a loop. Then, twist the string up by flipping the circle round and round. Pull the string outward and let it unravel. Watch it spin and the colors mix!

Magic 34

Amaze your friends with the Magic 34 trick! All you need is a grid with numbers 1 through 16. 

First, gather an audience and choose a volunteer. Next, say that you are a math mind reader and you can predict the sum of the four numbers they choose. Pretend to think, then, write the number down and put it in your pocket.

Directions:
1. Have them choose a number on the grid and circle it (any number).
2. Then, they cross off the numbers in the same row and column as the number they circled.
3. They keep choosing a number and crossing off the numbers in the same row and column, until they get 4 numbers.
5. They add their 4 numbers and you pull out the number (you wrote down) from your pocket. Is it 34?! 

Visit Learn With Math Games for the explanation behind this trick and for more math mind reading tricks!

Magic Grow Capsule: Math / Science

Check out Flap Jack Educational Resources for a magical area activity with grow capsules! Kids find the area of their animal sponge. Then, they construct a habitat for it!

Also, check out Science Matters for how you can use grow capsules to explore the scientific method (water temperature and various liquids).

Then, visit Fall into First to see how they used magic grow capsules to inspire them to write an animal report!

Is your number 18?

Magic Math Trick
1. Choose a number, any number!
2. Multiply the number by 100.
3. Subtract the original number from the answer.
4. Add the digits in your answer.
Is your number 18?!

Example: 
5
5 x 100 = 500
500 - 5 = 495
4 + 9 + 5 = 18

Now, let's try a larger number!
1,467
1,467 x 100 = 146,700
146,700 - 1,467 = 145,233
1 + 4 + 5 + 2 + 3 + 3 = 18
It's magic!

Check out Is your number 2? for more mind reading magic! For more math magic activities click here!

Toothpick Math Puzzles

Geometric "match stick puzzles" that help develop problem solving and critical thinking skills. For more puzzles to try, check out AIMS Center!

Walk Through Paper?!

Can you walk through a hole in an 8.5x11" sheet of paper? Pass out a sheet of paper to all of your students and see if they can figure out how to cut a hole large enough for them to fit through. Then, show them this magical trick! Visit Pleacher or The Math Lab for the how to (and a free printable with lines to cut the "perfect" hole)! Afterwards, stretch your paper out and try to find the area and perimeter of your paper! How did it change? For younger students, this project can tie into a basic measuring unit.

You can even fit through an index card! Click here for details!

Is your number 2?

Magic Math Trick
1. Think of a whole number 1 through 10
2. Double it!
3. Add 4
4. Divide by 2
5. Subtract the original number
Is the numeral 2?!

Also, check out Is your number 18?!

Visit The Math Lab for the algebra behind this math magic!

Domino Math Puzzles

NRich Math has LOTS of fun math puzzles to help develop kids' problem solving skills. All they need is a set of dominoes! Click here for the full list! Check out domino magic squares and rectangles here! If you don't have dominoes, you can find printable versions online.

Featured above:
Domino Multiplication
Domino Magic Square (Rows, columns, and diagonal share the same sum)
Domino Magic Window (All sides equal same sum)

Subtraction Squares

Fun, problem solving game for kids to practice subtraction skills from Learn with Math Games! This activity can be adapted to any age group. Younger kids can work with numbers less than ten. Older kids could work with 3 or 4 digit numerals.

Kids choose 4 numbers (anything they'd like) to write on the vertices of the larger square. Then, they just subtract (corner to corner). They write the differences on the next largest square's corners (where it meets in between on the line) and so on...

The big surprise is their final square! Like magic, all of the corners are the exact same numeral! Inference: See if kids can predict what will be their mystifying number before solving all their squares! Visit Learn with Math for a free template!

For more magical math check out:
Magic Square
Perimeter Magic Triangles
Calendar Magic 9

Magical Missing Addends

Now you see it, now you don't! Three hands on ways to explore missing addends!
Featured Above:
1. Paper Slider - Mrs. T.'s First Grade Class had fun figuring out the missing addend with a sliding bar! Click here for details, as well as for lots more awesome activities and printables!
2. Paper Peeker - Our Future is Bright created addition sentences with a mini flap for the missing addend. Visit her blog for a free printable!
3. Tell a friend to draw 2 cards and create an addition (or subtraction, multiplication, or division sentence) with a missing addend. Then, magically solve it right before their eyes!

Perimeter Magic Triangles

Perimeter Magic Triangles - Great addition, thinking game that deals with three addends! All you need are 6 milk caps labeled 1-6. Kids slide the milk caps around, forming a triangle. Their goal is to have all 3 sides add up to equal the same sum. For another milk cap addition game, check out Magic Square Milk Caps!

Calendar Magic 9

Impress your friends with this math multiplication magic trick from Murderous Maths! Kids tell a friend to put a square around 9 numbers on a calendar (3 x 3 box). Then, they say they can find the sum of the 9 numbers within the square in a flash! Abracadabra and alakazam! All they do is multiply the number in the center of the square by 9 and presto! They magically have the answer! 

Note: For larger numbers that may be hard to do the multiplication in your head, multiply the middle number by 10 and then subtract by the middle number. For example, 11 is in the middle, 11 x 10 = 110, 110 - 11 = 99! You can do this trick on any number grid!

Also, try Calendar Magic 20 trick, click here for the magic secret and other mysterious math tricks!

Magic Die

photo via alamy

Kids transform into magicians, being able to predict what number is on a die's bottom face, just by looking at the dots on top. All you need is one six-sided die. Roll it and say the number. Then, subtract the number from 7. For example, if you roll a 1, subtract 1 from 7. You get the number 6. Flip the die over, it's 6! This trick always works. No matter what the die lands on, always subtract it from the number 7. Impress your friends and work on your subtraction skills!

Magic Square

"Legend says an ancient Chinese emperor name Yu happened to be down by the Yellow River one evening when he noticed a turtle swim at his feet. The turtle had unusual marks on his shell which formed a magic square where all columns, rows, and diagonals summed to the same amount... 15. The 3 cell by 3 cell square grid pattern is called a Lo Shu magic square, representing the turtle star pattern and the Lo river." - Lo Shu Magic Square. 

A Magic Square is a great tactile, thinking game for kids, that has them rearrange three numerals (horizontal, vertical, and diagonal) so they all equal one sum, a magical number! I was inspired by Love 2 Learn 2 Day's milk cap magic square, so I made my own! Kids love the use of milk caps because they can slide and glide them around on a flat table top. Magic Squares are also a good way for kids to improve their addition skills using a group of addends, three whole numbers in an equation.