I have not been diagnosed with discalculia, but I am going through the process of getting tested for various learning disorders.
I am taking an evolution course, and right now we are focusing on microevolution which involves the Hardy-Weingburg equation. And, you guessed it, math. Luckly, there will be formulas on the test, but we can't use calculators because the math should be 'easy enough' for us to do without using one.
When I found this out, I internally freaked out. I can't even add 8+5 without doing it on my fingers! How am I supposed to work with decimals!?
I told my teacher this and that I was getting tested for LDs, but that I was really worried. I told him I can do really really simple math like the square root of 49, but I can't do anything more complicated then that. He asked if I could do the square root of .016, I think it was, and I responded with, ".004?" Which was wrong. He then told me what to do with the zeros, but he lost me. I nodded my head along like I understood, but really I had no idea what he was talking about. I asked him if I could use a spare sheet of paper and he said yes and I could also write all over the test. He also informed me that there will only be four questions involving math.
I think my game plan is to do all of the other questions first and save those involving math until last. Does any one else have any suggestions that might help me out?
I kinda don't know what to do at this point. I have an appointment tomorrow in order to get accomedations for testing, but I don't know if it is too late to apply those to my upcoming test which is on Thursday.
It shows you not only how you get the equation, but it also shows you a visual (the punnet square) to demonstrate the logic behind the formula. For me, I find that if I have something concrete that I can look at and see, "Okay, this is why the equation is the way it is" then it helps me remember it and remember how to do it properly. Since you will be given the formula on the test, that already solves half of your problem. The other half is figuring out how to do the math itself.
Here are some things that helped me figure out and remember how to do Hardy-Weinberg properly. I had to teach myself because my Biology teacher wasn't a very good math teacher, so I remember it pretty well as a result!
First of all, remember that the whole equation has to add up to 1. This is because the equation is talking about what percentage of a population is carrying what genes. The equation tells you what percentage are homozygous dominant (have two dominant alleles), heterozygous (have one dominant and one recessive), or homozygous recessive (have two recessive alleles). All three of those have to add up to 100%, or in the case of the equation, 1.00.
So for example, let's say that 80% of a population of mice has the genes for dark brown fur (in this case, 'B') and 20% has the genes for light brown fur (in this case, 'b'). That gives you 0.8 B and 0.2 b, because 0.8 stands for 0.80, or 80% of 1.0 and 0.2 stands for 0.20, or 20% of 1.0. If you add 0.8 and 0.2, they make 1.0.
Now you plug those numbers into your equation, and you get this:
p(squared) + 2pq + q(squared) = 1
0.8(squared) + 2(0.8)(0.2) + 0.2(squared) = 1
If you multiply 0.8x0.8, it's just like multiplying 8x8 except you move the decimal to the left two spaces (because if you add up all the numbers to the right of the decimal, you get 2, both 8's). So that gives you 0.64.
Next you have 0.8x0.2x2. 8x2 is 16, and 16x2 is 32. Now you move the decimal over 2 spaces again, because if you count the number of numbers to the right of the decimal in all your given numbers (0.8. 0.2, and 2) you get 2 total. That gives you 0.32.
Finally you have 0.2x0.2. 2x2 is 4, and you have 2 numbers to the right of the decimal so you move the decimal to the left 2 spaces. That gives you 0.04.
Now if you add up 0.64, 0.32, and 0.04, what do you get? 1.0, so you know you did all the math right because it adds up to 1. Now if you think of all of those numbers as percentages, it means 64% of the mice are homozygous dominant for brown fur (BB), 32% are heterozygous (Bb), and 4% are homozygous recessive (bb). You know it is in that order because p represents B, q represents b, and pq represents Bb.
I hope that somehow clears the math up a little bit for you. If it confused you more, then totally disregard everything I just said! That is what helped me to understand it, though, so I'm hoping maybe it'll help you a little. Good luck on your test!
"The hardest arithmetic to master is that which enables us to count our blessings." - Eric Hoffer
Location: Texas USA Posts: 6098 Joined: 2008-05-25
Kat would probably know whether a calculator can help in this circumstance, but I just wanted to 'chime in' and say that, naynaybeluga, if you have been tested and diagnosed with Mathematics Disorder, and if you have your paperwork 'in place' at the DDS office, then it is not 'up to' your teacher to decide whether or not the math is 'easy enough without a calculator'. Your documentation supercedes the teacher's assessment of what should be 'easy enough' for you without a calculator. But again, since I haven't taken the course, I don't know whether the type of math involved lends itself to 'assistance' from a calculator.
Also, are you in the US? - jus'
Edited by justfoundout on September 28 2010 11:15 PM
Location: Texas USA Posts: 6098 Joined: 2008-05-25
<chuckles> No, you can't change the past. That makes me laugh as it reminds me of a funny monologue that I once heard on the radio. It was a country-fied, grumpy-old-man talking. In it he said that someone had told him that he 'wasn't getting any younger', and the old man said he'd retorted, "... be in the circus if I was!".
So, if you find a way to 'change the past', you'll please let the rest of us know? So many times I've 'changed the right answer to the wrong'. - jus'
Edited by justfoundout on October 01 2010 08:43 AM