X-RAY EYES! MULTIPLICATION MAGIC

Hi All,

This is not a big time math lesson, but kids love a good magic trick they can do, so here it is. This one uses the sevens times table and is a snap to learn.

*Tell students that if they roll a pair of dice you will be able to tell them the total of all the top numbers and bottom numbers (without looking at the bottom) because of your "x-ray eyes."

*The secret is that on any die, the top number and the bottom number always equal 7. Roll two dice and the total is going to be 14. Roll three dice and it will be 21. Four dice will be 28, and so on through the 7 times table.

*Begin with students rolling two dice, then three, then four, and let them use as many as you have available. See if they can figure out the trick.

*Once they figure it out (or you reveal it), they can practice and then take their "multiplying magic show" on the road and share it with others.

Simple, but fun. Oh, and keep the dice handy, on Thursday we'll get "Deeper with Dice."

All the best,
Bob

Adapted from Mathemagic by Raymond Blum (Sterling, 1991)

Comments

THE FOUR FOURS!

Hi All, Here's a mathematical exploration that will literally make kids want to know what a factorial is and how to use it! I know, crazy, right? But, true! I love this one. It is particularly good for a class that is learning about order of operations, so typically 5th or 6th grade, but you can use it all the way through high school because it is just so darn intriguing and fun. You should try it too. It does give your brain a workout, and makes you think flexibly with numbers. The premise is simple. You get four "4's." Using any of six operations; addition, subtraction, multiplication, division, square root, or factorials, write mathematical expressions to represent all the integers from 0 - 25. You may use operations as many times as you want and you may use a variety of operations within an expression. You can also use brackets and parentheses as needed. For example to represent 16, you could write 4 + 4 + 4 + 4 Remember, 4 is the only digit you can use...

BAD Graphs

Hi All, Kids love to find other people's mistakes. (Not always that keen on finding their own of course.) Here's a chance for them to find some mistakes while learning some things about graphs. This activity focuses on learning about graphs and the parts of a graph that are important, but are sometimes neglected. When kids make their own graphs the most common omissions are: the title (what is this a graph of?), labeling the x and y axis (what do numbers and bars means?), and the units (how much of what?). A great way to remind kids of the importance of these elements is to have them try to deal with graphs that don't have them ie; BAD graphs. I give students a worksheet on which I have created four BAD graphs. They are BAD graphs because I leave off important elements like the title. Along with this students are also given a 4 item question sheet which they are to try to answer using the BAD graphs. I put the BAD graphs on the board or display. They look like this: I...

EGG BOX SHAKE! IT'S WHATEVER YOU WANT IT TO BE.

Hi All, Shake it up! Egg Box Shake is noisy and fun! That's a big plus right there for most kids. Students like to create and keep their own math tools, and this is a great opportunity to do that as well. And, teachers can adapt the game to fit any level or mathematical operation. Win. Win. Win. Egg Box Shake originated as a coin identification and addition game for grades 1 – 3. I had students bring in an egg carton from home and then provided them with play money or coin stamps, ink pads, and card stock. They stamped out pictures of the coins onto card stock, front and back images, and then cut out the pictures. Students glued these pictures into the bottom of the twelve sections of the egg carton. Each player would get two beads, beans, chips, marbles, or any other small manipulative. They put these into the box and closed it. They then shook the box. When they stopped they opened it and saw where the beads had landed. Players added those two coins o...

MathStuff

Search This Blog