Do you keep struggling to teach common denominators? Do your kids just not “get it”? Well, it’s time to quit. Yep! You can teach (and do) fractions without ever finding a common denominator. The key is in the definition of addition for rational numbers. If you have two numbers and the sum of them is . Granted… Continue Reading →
Category Archives: Arithmetic
How to Use Prime Factors to Cancel Fractions
I previously posted about prime factors and about using them in multiplication. Now we’ve got fractions to handle. Before we get in too deep, first let me note the main reason why we do this with arithmetic. In algebra, students will be asked to take a rational expression, factor it and reduce it like this:… Continue Reading →
How to Use Prime Factoring to Win Friends and Influence People
Alright, you might not win friends with this, but the more you can do arithmetic in your head… well… okay, you can’t influence people with it either. Regardless, it’s handy to know and helps with multiplication. Yesterday I posted a couple of videos about factoring numbers into primes. Now it’s time to put those to work.… Continue Reading →
2 Ways to Factor Numbers into Primes
Factoring is traditionally considered an “f-word” for students of math. But it really has its good sides. First, here’s two ways to do it with regular numbers. Continue Reading →
How to Check if a Number is Divisible by 3 or 9
Can you quickly tell if a number is divisible by 3 or by 9? With this trick you can impress everyone – well, not EVERYone, but a few anyhow. Continue Reading →
2 Ways to Multiply Mixed Numbers
Multiplying fractions provides an interesting challenge. Put some mixed number into the situation and you could be facing a real bear. Here are two ways to do it. Continue Reading →
How to Convert Mixed Numbers to “Improper” Fractions
Converting back and forth from improper fractions to mixed numbers isn’t something you do everyday. Here’s a helpful way to remember it long term. Continue Reading →
How to Multiply By Hand Without Hurting Your Brain
The Distributive Property isn’t just an Algebra thing. You can use it for regular numbers. And the more you practice with regular numbers, the better you’ll be in the Algebra! Continue Reading →
How to Subtract Using Reverse Addition
Do you learn to “borrow” when you subtract? How about reverse adding? Some schools have gone to this new method and gotten rid of the borrowing concept. Here’s how it works. Continue Reading →