Born to Run

Which one is the radius...

and which one is the diameter?

I remember the radius as the one that starts in the 

middle...

...and then RUNS to the outside.

The diameter crosses the entire diagram.

That's it. Work smart, not hard.

Mixed Fraction Subtraction - Let's Go Shopping

Mixed Fraction Subtraction - kinda rolls off the tongue, doesn't it?

OK - how about...?


     4
5  ---
     7

subtract

     5
4  ---
     7


We know the 4 and 5/7 is smaller than the 5 and 4/7.

But how to subtract 5/7 from 4/7?

Some might suggest converting both fractions to improper fractions...

...and coming up with 39/7 - 33/7 

...and arriving at 6/7.

However, if you are not particularly strong at multiplication, you might try this method...

Let's go shopping...

     4
5  ---
     7

First off - let's just make the 5 one LESS.

Why?

1) Because we can.
2) You always come away with LESS money when you go shopping. (Yes, yes, yadda, yadda, you might end up shopping for lottery tickets and win. Heard that one. Heard 'em all.)

So now our fraction is modified a bit from

     4
5  ---
     7


To...

     4
4  ---
     7


But not for long. Now let's buy a top.

Hmm, stylish. Who said I had no taste?






OK. Now remember...our top (denominator) was 4.

Better now add some pants to this stylish ensemble.

Let's add the
bottom (pants) to the
top. Can this ensemble get any more stylish? I doubt it. 


4  add  7 = 11










Remember...
     4
5  ---
     7


changed to...

     4
4  ---
     7

and we are now going to add the pants (bottom) onto the top

4  add  7 = 11


    11
4  ---
     7

Now we can finish the question.

    11
4  ---
     7

subtract

     5
4  ---
     7


Let's get rid of those whole numbers...
4 - 4 = 0

Now...

11/7 - 5/7 = 6/7


6/7 is our answer. Work SMART, not HARD!

We're Not Gonna Take It!

"We've got the right to choose it
There ain't no way we'll lose it." (Twisted Sister)



O.K. - I found these tips from- Basic mathematics.com

And it makes sense. Why take the question the way it is given to us?

Why not twist or rearrange things to our advantage?

Examples of additive compensation

Add 97 + 64

It may not be easy to add 97 and 64 mentally. However, one small adjustment

such as rewriting the problem as 97 + 3 + 61 can help us to get an answer quickly

97 + 3 + 61 = 100 + 61 = 161

Add 25, 27 , and 18

It is not easy to do any of these additions mentally.

25 + 27            25 + 18         27 + 18                             

However, if we take 2 from 27 and add that to 18, the problem becomes

25 + 25 + 20 and this is very easy to do mentally since 25 + 25 = 50 and 50 + 20 = 70

Examples of equal additions method

 The equal additions method is a compensation used when doing subtractions.

Subtract 39 from 57.

57 - 39 can be thought of as  58 - 40

58 - 40 = 18

To make the subtraction 58 - 40, we added 1 to 57 and 39 so that we still have the same subtraction problem.  

Work SMART, not HARD!

Is it Prime (Or is it Memorex)?

A prime number is a natural number greater than 1, that has no positive divisors (factors) other than 1 and itself.

If you think of this definition in pictures of rectangles...

2 - ᥆᥆
3- ᥆᥆᥆
4 - ᥆᥆᥆᥆ or  ᥆᥆
                       ᥆᥆
5 - ᥆᥆᥆᥆᥆
6 - ᥆᥆᥆᥆᥆᥆  or ᥆᥆᥆
                             ᥆᥆᥆

Any number that can ONLY be represented by a straight line is prime.

Straight line is prime.

Integer Football Game

I came across this cool way to explain integers. Integer football. See for yourself at...

Integer Football

Fractions for Math Teachers

Pass The GED - Tips and Tricks

Many times it is the little things that stand between passing and failing. 

Here's a video to help everyone pass the GED exam by dealing with those little things.

Find the video here.