In a previous post, we learned that you don’t have to use a LCM (least common multiple) to find a common denominator to add fractions. In another post, we learned that you can use primes instead of the GCF (greatest common factor) to reduce fractions. And now I’m going to demonstrate that finding the LCM… Continue Reading →
Adding Fractions: Why Avoiding Common Denominators Works
I wrote this post showing that adding fractions can be done using the algebraic definition of addition of rationals: MathHeadInc (via twitter) has requested a video showing why this works. I aim to please. Here is the video showing why adding fractions using a common denominator is the same as the definition of addition of… Continue Reading →
How to Use a Student’s Experiences to Teach Math – The Story of a Former Drug Dealer
A quarter pound of drugs is 1/4 of a pound! Image via Wikipedia Do you have an especially difficult student? Does one kid stand out as just not getting it? The answer lies not in your approach, but in their perception of their own capabilities. My Former Drug Dealer Student I was teaching Oilfield Math… Continue Reading →
Teaching Math without Rules: Addition of Positive and Negative Numbers
I’ve discovered many ways of teaching math through the years and the most interesting one was the addition of numbers with opposite signs. I learned this from a teacher who said that he never understood the rules – so he made up his own method. He “breaks” the bigger number into two pieces so it… Continue Reading →
Why It’s Okay to Teach Algorithms
We had a lively discussion at last week’s homeschool math chat about teaching algorithms versus allowing a discovery learning process. What I can’t help but think about when I reread this discussion is how this compares to teaching a child manners. Teach kids manners early. Very early. I know someone who elected to wait until… Continue Reading →
Why Focusing on Grades is Okay
David over at Real Teaching Means Real Learning posted last month about the focus of learning over grades. In principal, I agree that learning should be first in the minds of children and grownups. In principal. But this is reality. And I have two issues with David’s opinion. The conversation points for each focus is… Continue Reading →
Quick Addition Tip – Adding 5 to Larger Digits
For some reason I have trouble adding 5 to the larger digits (like 7, 8 and 9). I noticed at some point that the last digit of that addition is the same as if you subtracted 5 from that number. Like this: 7 + 5 = 12 7 – 5 = 2 and 8 +… Continue Reading →
How a Math Teacher Can Change Lives
I was in the 4th grade. We were studying geometry. Mrs. Wilburn was the teacher. I read the definition of a square in the textbook: A square is a polygon with four equal sides and four equal angles. I read the definition of a rectangle: A rectangle is a polygon with four sides and four… Continue Reading →
Math Teaching Find of the Week: Marilyn Burns
There are so many programs out there to help kids learn math. But kids will learn math, naturally. Especially if they see it as an organic thing that is part of their world. Just as we all are potty trained, we all do math. It just is. MathFour.com isn’t another “teach math” site. My mission is… Continue Reading →
How to Never Find a Common Denominator Again
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 →