Calculator fun

Calculator fun.

Calculators are no substitution for knowing your facts, but sometimes they can be used to make some fun mathematical discoveries.

For grades 1-3

Try multiplying any number by 10.  What do you notice?  Now try multiplying by 100.  Now 1000.  Think you could do it without a calculator now?

Grades 4-5

Same as the younger kids, try multiplying any number by 10 then 100 then 1000.  Seems pretty simple doesn’t it.  You might not need a calculator.  Before you make up a rule though, try multiplying a number like 4.7 by 10, then 100 then 1000.  Now try 2.587. 

Once you feel that you can come up with a rule, try dividing by 10, then 100, then 1000.  Can you figure a rule out for that?

Grades 6-8

Alright, get out you calculator but also paper and pencil.  I’ve got two tricks you might find pretty cool.

Start with a two digit number, like 35 and multiply it by 11.  When you get the answer write it down making the middle number a different color.  Try this several times.  You should start to see a neat pattern forming making it easy to multiply any two digit number by 11 without a calculator.

Now check this out.  Take any two digit number ending in 5, like 45.  Square it (multiply it by itself.)  Write down your answer.  Do this again several times.  What do you notice?  It might take a little while and you may need to ask your parents for some help, but a real nice pattern is there. 

Math Circle Fun

Circle Fun

Grades 1-3

You'll need a ruler for this.  Near the center of a piece of paper make a dot.  Now, measure a distance in any direction from that dot and make another dot.  Do this again measuring the same distance from the original dot now in a different direction.  Keep going back to the same dot and measuring the same distance only in different directions.  When you've done this many times, say at least 10, connect the outer dots.  What if you did this a million times?  What do you think it would form?

Grades 4- 5

Cut a regular piece of paper into strips 3 inches wide.  Roll them up to make 3-inch long tubes less than 2 inches in diameter.  Now, using another piece of paper,  Using either a compass or simply a piece of string, make a circle with radius 1 inch, then 2 inches, then 3 inches and so on.  Cut the circles out to form disks.  Between each disk place a tube and see how high you can build a tower.


Grades 6-8

Using a sewing tape measure, find a something circular in the house.  Measure the distance around the circle.  Now measure the distance across at its widest point (diameter.)  Next take the distance around (this is the circumference) and divide by the diameter.  Record your answer.  Repeat with other circular objects recording your answer each time.  Do you notice something happening?  Anything familiar?

Junk Mail and Mail?

Grades 1-3

Count how many pieces of junk mail make it to the recycling bin each day.  Compare the number of pieces of junk mail to other mail.  Make a big comparison at the end of the week.

Grades 4-5

Junk mail can be pretty heavy.  Keep track of the junk mail that ends up in the recycle bin in your house.  At the end of the week, hold it all while you stand on a bathroom scale.  Then weigh yourself and subtract.  This is how much weight your family recycled in junk mail this week.  Multiply by 52 and you’ll have an idea of how much junk mail comes to your house every year. 

Grades 6-8

Does one day of the week generate more junk mail than the others?  Try setting up a simple line graph for a couple of weeks.  Record the number of pieces that your family receives each day.  Make a prediction for the third week and see what happens.

Measuring up

Grades 1-3

Take a sewing tape measure outside and into the woods.   A fairly loose way to determine the age of a tree without cutting it down and counting rings is to measure the circumference (distance around.)  A tree’s age in years is approximately the same as its circumference in inches.

 

Grades 4-5

Find a can of paint in your house.  Read the label to see how much area can be covered with one can.  Using a tape measure find a part of your house that could be covered by one can of the paint.  Kids, this is a math question.  Please don’t see how much the can will cover by actually painting!

The same could be done with grass seed.  How many bags you will need to seed your whole back yard?

 

Grades 6-8

Ruler Guestimation – Just like guessing a number between 1 and 100 only you are trying to find a number between 1 and 12 on a ruler.  These numbers, however, include all the fractional parts of an inch.  For example, 

The number to find is 6 9/16

Guess: 6

Response: higher

Guess : 7

Response: lower

Guess: 6 ½

Response: higher

Guess: 6 3/8

 

And so on.

Rolling the Dice

Rolling the Dice

Using simple tools such as a die or dice is a great way to have children learn their math facts. Here are some simples ways to have children learn addition, multiplication and for more advanced students, try the game of the "24" to challenge knowledge of order of operations.

Materials Needed:
Grades 1-3: 2-3 dice
Grades 4-5: 2-3 dice
Grades 6-8: 4 dice

Grades 1-3
The basic starting point for using dice for learning and reviewing math facts is to have the child roll two dice and add them together. Have the child keep track of each score. Whoever reaches 500 first wins.

If your child has advanced beyond that point, make it more challenging by using three dice. Roll the first die for a target number. Then roll the other two dice until together they add up to the target number of the first die. Add all the various rolls together and the person that has a total of 500 first, wins!

Grade 4-5 

The basic starting point for using dice for children in Grades 4-5, is to roll two dice and have the child multiply them together. If you child is more advanced, have the child roll two dice and add them together and then repeat. Then multiple the two sums. Keep track of each score and the first person to reach 500 first, wins!

Grades 6-8

24 Game
Roll four dice.  Take the four numbers you rolled and use them to make 24.  You can only use the four numbers, but you can use them in any way.  For example:

You roll 6 , 9 , 3 , 2.  
6 + 9 + 3² = 24
You roll 1 , 4 , 9 , 2
2(9 + 4 – 1) = 24

 This activity can be particularly challenging for some number combinations but nearly every one can be done.

These are great ways to keep your math facts sharp throughout the summer.  Have fun with it and keep checking back here for weekly activities that make math fun.

Math Quotes

"I believe that if you show people the problems and you show them the solutions they will be moved to act."

~ Bill Gates

Grade 3-8: Art in Math - Origami

Origami is a Japanese artform originating in the 17th century meaning "ori" folding and gami" folding. The object is to create forms using folding paper without scissors or glue. 

Extreme origami

Erik and Mark Demaine win the Guggenheim award for their curved-crease sculptures. The Demaines used origami to be a powerful tool to study mathematics, the father-and-son duo explore foldable forms from both mathematical and artistic perspectives. This concentric circle shape can be traced back to the Bauhaus, which the Demaines have extended further by pushing multiple concentric circles together. 

Their mathematical origami was on view through January 2014 at the Museum of Modern Art’s Applied Design collection.

Grade 6-8: Art in Math - Geometry in Art

Hyperbolic lampshade by Gabriele Meyer
In the April 2014 issue of Discover Magazine the bridge between art and mathematics is explored where artists use equations and geometry to create beautiful works of art.
Visions of Math

The  Bridges Organization, oversees the annual Bridges conference on connections between art and mathematics. 

Bridges began in Kansas in 1998. Since then it has traveled to cities in North America and Europe, and has attracted participants from over thirty countries. The conference features invited speakers, full and short paper presentations, educational workshops, a juried art exhibition, a mathematical poetry reading, and a short movie festival.

Happy Pi Day!

March 14! (3.14)

Grade 1-8: Contest - Doodle 4 Google

Since 2008, Google has been hosting a doodle contest for children K-12. Each doodle must be submitted on an official entry form. Hand drawn entries are fine as well as the use of Photoshop. 

Create your doodle in a new document 1894 pixels high by 2960 pixels wide at 300 dpi. Eligible Doodles must be two-dimensional and scannable.

The contest takes place between February and March each year. There is an opportunity for the public to vote through April and then judges view entries from all 50 states with winners announced each June. 

To inspire the creative process: 
There are also various fun activities set up in partnership with Discovery Education, are designed to help K-12 classrooms (and individuals) stretch their creative muscles and warm up for the Doodle 4 Google competition.

Thomas Edison once said, “To have a great idea is to have a lot of them.” 

Activities for Grades K-2
Activities for Grades 3-5
Activities for Grades 6-8
Activities for Grades 9-12

Grades: 6-8: Art in Math- Making Art Using Equations Autologlyph

According to Discover magazine many artists use calculations and numerical analyses as a rich source of ideas and methods for their creations.

This is a self-referential bunny — a sculpture of a bunny, the surface of which is tiled by 72 copies of the word "Bunny."

This piece is part of a larger series of "autologlyphs," following on from HS's "Sphere Autologlyph" from the 2010 Bridges art exhibition. An autologlyph is a word written or represented in a way which is described by the word itself. This style of autologlyph combines Escher-style tessellation with typographical ideas related to ambigrams.