Glossary: The N2 Math Dictionary

Finally. A glossary. An N2 Math glossary. If you had a hard time understanding some words in lessons, more often than not, that word will be in this glossary. Any words in bold-faced print will be in this glossary. When a new lesson is released, this glossary will be updated. Enjoy!

subtraction - The second kind of arithmetic. Subtraction is when we take a certain amount from a number. See the subtraction lessons or Khan Academy for more details.

subtract - This is what we do in subtraction. Subtract is the verb form of subtraction, which is a noun. See the subtraction lessons or Khan Academy for more details.

add - This is what we do in addition. Adding is combining one number with another. For example: 3+2=5. See the addition lessons or Khan Academy for more details.

sum - The answer of an addition problem. For example: the sum of 2+3 is 5. See the addition lessons or Khan Academy for more details.

carry - This is something that we do in addition and multiplication. When we carry, we're taking a number into the next column and adding it to the sum (total) of that column. See the addition lessons, multiplication lessons, or Khan Academy for more details.

Division 1: The Big Challenge Begins!!

Now we face the big challenge that I've been talking about, although at first it won't be super hard.

Division is the opposite of multiplication. In division, we divide one number by another. Our problem this time is gonna be 8 divided by 2. What this means is that we're gonna divide 8 into 2 groups. In other words, the question to ask ourselves is, what times 2 equals 8? Well, there isn't much of a good way to walk you through this, because there's really just a flat out answer for this one. And it is...
4!! Do you know why? Well, 4x2 is 8, and so 8 sliced in half (2 groups) would be 4!! If you don't understand this, or disagreed with this answer, I would recommend Khan Academy. You might want some practice.

OK, you've now mastered the basics of the big challenge, division. But can you overcome the obstacles that lay ahead?

We'll find out the next time we get deeper N2 Math!!

Multiplication 2: Step By Step Like an N2 Mather

Oh, boy. Now it gets harder. Are you up for the challenge? Let's go!

Today we're gonna work on multiplication again, but this time, it's a little different. Remember when we did multiplication in the last lesson? Remember how in the last one we did 3x3? That was multiplying by just one digit. Now we're gonna multiply by TWO digits. This time, I'll write out the problem and give you a step-by-step guide on how to do it. Hopefully it will help you learn this type of multiplication. Ready? Here we go.

        45
x      32

First, we start out with the number 2, and multiply it by 4 & 5.

        45
x      32
          0
Oh, oh. 2x5 is 10!! But we can only fit only ONE digit in that section!! This is a time where we have to  carry.

        1
        45
x      32
          0
Now, back to where we were before. Don't forget, we need to add the carried number to the sum of this part.


        1
        45
x      32
        90
Now that we're done with this part, we need to go to that second digit. But before we do that, we need to erase (or delete, it depends on what you're using) that one that we had carried.



        45
x      32
        90
But now we need to add another row, and before we start adding with that one other digit, we need to put a zero there. This is because this digit is a ten.



        45
x      32
        90
          0
All right, now we can start multiplying.



        45
x      32
        90
        50
Wait, 3x5 is 15?! Don't forget about carrying!!

        1

        45
x      32
        90
        50

OK, back to the problem at hand. Don't forget about that carried number!!

        1

        45
x      32
        90
    1350
Now what do we do? Well, we're going to add the 2 numbers at the bottom. We won't have to erase that 1 at the top because it won't be in our way. You ready? Let's go!!


        1

        45
x      32
        90
+  1350
        40
Don't forget about carrying!! We'll also need to add that carried number to the sum of this column.


        1

        45
x      32
      1
        90
+  1350
      440
Last part!! Here we go!!



        1

        45
x      32
      1
        90
+  1350
    1440
So 1,440 is our total. We beat the challenge and pushed through multiplication!! AWESOME JOB!!!!
Next time we'll be facing an even greater challenge...
Join me as we get even deeper N2 Math!!

Happy New Year!!

I know, this isn't a lesson, but I just wanted to wish everybody a Happy New Year. It's been a great year, and I hope you've learned a lot so far. In 2013, I hope that I find better and more intuitive ways to teach you math. Again, Happy New Year to you.

By the way: I'm working on the 2nd multiplication lesson. It'll probably be up later today, if I have time.

Multiplication 1: Some Groups of This, Some Groups of That,

Wow. You're now halfway through the 4 kinds of arithmetic! Keep it up!

Today we'll learn a new kind of arithmetic. This one is called multiplication. You probably won't have trouble with the basics, but believe me, it gets a lot harder.

Multiplication is when you multiply in groups of itself. It's mainly just a writing shortcut for an addition problem at first. The problem we'll be working with today is 3x3. This means the answer will be the sum of 3 groups of 3. In the first group, we start out with 3. Then we add another group of 3. Can you guess what that would be? If you just said 6, you're right! If not, it's about time you went to www.khanacademy.org. It could really help you understand this concept better. Now, back to the problem. We now have 6, but we need to add yet another group of 3! Add 3 to 6, that would be 9! For those of you who got this right, keep up the good work! If not, please go to Khan Academy by clicking the link above. OK, now that we're done with this problem, what is our answer? Look back at the last number that I wrote. That, of course, would be 9!

Thank you for joining me while get deeper N2 Math!!

Subtraction 2: Testing... Testing...

Great job! Now you know the simple basics of subtraction, and you know how to borrow! Now, we'll practice even more subtraction! This time, instead of me getting you through the problem, I'll give YOU a problem to work on! All right, here we go...

   34

  -27

OK, now that you're done working on this problem, let's give you a grade on a scale of 1-10.

Key

32+ = 1

27-31 = 2

22-26 = 3

17-21 = 4

12-16 = 5

1-3 = 6

4-5 = 7

8-11 = 8

6 = 9

7 = 10

7 is the correct answer. If you got a grade from 1-5, I really recommend www.khanacademy.org.

Thanks for joining me today and I'll see you on the next N2 Math lesson/test!

Subtraction 1: May I Borrow Some of Your Numbers?

OK, so now you know everything you need to know about addition, but now we're headed on to subtraction. Subtraction is when you take away numbers instead of adding numbers. Let's say we have 10, and we subtract 7. Like addition, we start with the unit column. Zero - seven. Because we cannot take 7 from zero, we need to borrow from the one in the ten column. We would turn that one into whatever number is one less than the number. In this case, that number would be zero. We put the one behind the zero in the unit column to make that zero a ten. Now, what is 10 - 7? If you need help, here's how to do it: with subtraction, we need to count down seven numbers from 10, because we are taking away numbers. Like addition, we don't count 10. OK, let's start counting down. 9, 8, 7, 6, 5, 4, 3, STOP!! We've now taken away 7 numbers from 10. What was the LAST number we counted? If you said 3, you're right!! If not, you might want to watch some videos on www.khanacademy.org or you could read this lesson over again and you might understand it. If you now understand it, awesome!! You're all on a great path!! Addition and subtraction are the first out of all arithmetic you'll learn. In time you'll be masters at these two subjects. Until the next lesson, see ya!!