Welcome to my page/half page on Reflex Math as well as the landing spot for those who missed question 7a of the aMAZEing Math Maze. Let's start with information on the Maze.
The formula we were trying to factor is12x2 - 4x - 40
The very first step when trying to factor is to look at the coefficients. In this case they are 12, -4, and -40. Can all three of these numbers be divided evenly by a number? They are all even, so we know they can all be divided by 2. The smallest coefficient is 4, will 4 go into the other two numbers evenly?
That changes things, now we're looking at the equation4(3x2 - x - 10)
Let's look at the possible answers
a) 4(3x - 5)(x - 2)
b) 4(3x + 5)(x - 2)
c) -4(3x + 5)(x + 2)
d) (3x + 5)(4x - 8)
We can safely eliminate d). It's not completely factored because we didn't factor out a 4. Answer c) shows that we factored out a negative 4, but the first coefficient was 12. We factored out a positive 4. The answer must be either a) or b).
In a) we will be multiplying 3x times -2 and -5 times x, so that's -6x and -5x for a total of -11x, (We're just talking about the middle terms, we don't care about the x squared or the last term that doesn't have an x. These will be the same for both a) and b).
In b) it will be 3x times -2 and 5 times x, or -6x and 5x for a total of -x.
4 times the -11x we got in a) is -44x and that is not the middle number of the equation.
The correct answer has to be b) - remember, we factored out a 4. When we multiply 4 times -x we get the middle term of the formula -4x.
Frankly, I had never heard of it. But, when I looked at it's site at www.reflexmath.com it looks pretty good. They are not paying me for this endorsement and I have not yet tried it. But I am recommending it to my school district. From what I have been able to figure out, they offer games that allow children to learn the basics. Reflex Math might be a really neat product.
I have taught kids in college that didn't know their multiplication tables. This is must have knowledge and flash cards can't do everything. Flash cards were kind of fun when I was a kid, but so was black and white television with three stations. Three's a free trial and it looks like it will cost about $35 per student per year.
Let me know what you think if Reflex Math is a product you intend to try. Hmmm, I wonder if I could get $10 a year for the aMAZEing Math Maze?
XVII.. Square Root Functions
XVIII. Absolute Value Functions