# Talk

## can anyone direct me to explanations of binary numbers for kids?

(44 Posts)
megletthesecond Fri 01-Apr-16 21:47:16

It needs to be thicky level of explanation because I need to understand them before I read a kids computing book with 9yo ds.

Does anyone know of any clever YouTube vids about binary numbers? Thanks.

ItsAllGoingToBeFine Fri 01-Apr-16 21:52:17

Any use?
youtu.be/hacBFrgtQjQ

janethegirl2 Fri 01-Apr-16 21:54:57

No but binary is quite easy
1 in binary is 1
2 in binary is 10
3 in binary is 11
4 in binary is 100
Basically it works on the power of 2
So you work from right to left ( like any number base)

So if you want 8 in binary it is 1000 etc

Hope that helps, just don't ask about Octal but it's similar, for Hex you get calculators that do it for you.

ILeaveTheRoomForTwoMinutes Fri 01-Apr-16 22:02:43

how do you get to 8 is 1000?

I was half expecting to see binary (the mner) to be answering on this thread.

ToastyMcToastface Fri 01-Apr-16 22:05:54

We count in base 10 because we have 10 fingers. So imagine you only have 2 fingers. 1 is 1, but as soon as you get to your second finger, you are into the 'tens' column, so 2 is 10. The maximum number you can have in any column is 1, whereas in base 10 it's 9.
So it counts up as
1
10
11
100
101
110
111etc.

It's used in computing as 0 and 1 represent the states of switches - they can be either on or off.

user7755 Fri 01-Apr-16 22:06:32

Jane - quite easy?

That might as well be chinese writing for the amount of sense it makes to me!

janethegirl2 Fri 01-Apr-16 22:07:45

With 4 being 100
5 is 101
6 is 110
7 is 111
8 is 1000
Sorry can't make it simpler, with binary you can only use 1s and 0s
9 is 1001
Does that help or make it clear as mud?

ILeaveTheRoomForTwoMinutes Fri 01-Apr-16 22:09:17

Got it, I think, now I can see the sequence,
Got ds1 explaining now too

janethegirl2 Fri 01-Apr-16 22:10:29

Can give more examples if necessary. Fortunately I don't need to use binary too often

megletthesecond Fri 01-Apr-16 22:15:53

itsall that vid helps actually . It's too late on a Friday to really understand it but I have a glimmer of hope now.

It's like I have to 'forget' base ten to find my feet with binary.

janethegirl2 Fri 01-Apr-16 22:18:06

All bases work similarly. If you really understand how one works, all are very much the same.

ILeaveTheRoomForTwoMinutes Fri 01-Apr-16 22:20:39

OK DS drew a diagram based on 5 spaces /
number's.

16|8|4|2|1 these create any number up to 64

For the one it's like this

16|8|4|2|1
0|0|0|0|1

Three would be

16|8|4|2|1
0|0|0|1|1

14 would be

16|8|4|2|1
0|1|1|1|0 you have zero 16, one 8, one 4 = 12 plus one 2 = 14

Think I understand that

CrotchetQuaverMinim Fri 01-Apr-16 22:22:56

Think of the different columns as place value, the way you do in the tens system.

In the tens system, the first column (assuming no decimals!) represents units/ones - whatever digit there tells you how many ones you have (which is 10 to the power of 0)

The column to the left of that tells you how may tens (which is 10 to the power of 1), so whatever digit is there tells you how many tens there are.

The column to the left of that tells you how many hundreds (which is 10 to the power of 2), so whatever digit is there tells you how many hundreds there are.

The column to the left of that tells you how many thousands (which is 10 to the power of 3), so whatever digit is there tells you how many thousands there are.

and so on. It sounds really obvious in base 10, because it's how we name our number - so obviously 8362 means eight thousands, three hundreds, six tens, and two ones. You can only have up to the digit 9 in each column before you have to go to the next one.

But you can also label the columns in base 2 (binary) like that.

The first column tells you how many ones (which is 2 to the power of 0).

The column to the left of that tells you how many twos (which is 2 to the power of 1).

The column to the left of that tells you how many fours (which is 2 to the power of 2).

The column to the left of that tells you how many eights (which is 2 to the power of 3).

So if you have a number like 29 that you want to put into binary, you can make a little table where you label the place values (which probably won't format right on this, but just imagine 5 columns):

2^4=16 2^3=8 2^2=4 2^1=2 2^0=1
1 1 1 0 1

You need the biggest of those that you can fit into 29, which is 16, so you put a 1 in that column. That leaves 15 left. So you can fit an 8, so you put 1 in that column. That leaves 5. You can fit a 4 into that, so you put a 1 in that column as well, leaving you 1. So you can't fit any twos in that, so that column gets a 0, and the righthand column, the ones, gets a 1.

In other words, 29 is made up of 16+8+4+0+1, written in binary as 11101.

If you want to do in reverse, and take a binary number like 10010, you just plug it into the same columns, and add it up:
so that's one 2^4 = 16, no 2^3, no 2^2, one 2^1 = 2, and no 2^0. So 16+2 = 18, in base ten.

I'm sure someone else will have posted a better explanation by the time I've finished typing this!

megletthesecond Fri 01-Apr-16 22:24:29

I think I understand it now!

Thanks everyone.

janethegirl2 Fri 01-Apr-16 22:25:45

Yes *I leave the room*thats a good way of explaining it. I couldn't think how to put it like that on the screen.

CrotchetQuaverMinim Fri 01-Apr-16 22:28:30

And to do any other bases, you just replace the powers of 2 or 10 with the powers of that number.

user7755 Fri 01-Apr-16 22:29:09

I think I get it, but why bother? It sounds terribly complicated!

ILeaveTheRoomForTwoMinutes Fri 01-Apr-16 22:29:11

Sorry DS says those numbers will take you up to 31

I'm lost again now, especially now he telling me about the alphabet

CrotchetQuaverMinim Fri 01-Apr-16 22:33:14

The advantage of binary is that you can represent any number with a series of only two possible digits (0 or 1), which can translate to e.g., electronic systems that have two states (on or off). You couldn't easily do that if you have to have 10 different states for each switch (corresponding to 0,1,2,....9).

The disadvantage of binary is that it takes a lot more places to represent even small numbers (i.e., 5 places will still only get you up to 31), whereas in base 10, you can get up to 99,999 with 5 places.

The smaller the base, the fewer digits/symbols/states you need, but the more places. The bigger the base, the more digits/symbols/states you need, but the fewer places.

Ramaani Fri 01-Apr-16 22:33:17

Line up a row of (say) red Lego bricks (represented as H) thus

[
[ H H
[ HHHH
[ HHHHHHHH

And so on - doubling the pile each time.

Then get your DS to give you a random number of (say) blue bricks BBBBBBBBBBB

Then fit the blue bricks on top of the red bricks working from the longest row following the rule that you can only put blue bricks down if you have enough in your hand to fill the row

[B
[ H H
[BB
[ HHHH
[
[ HHHHHHHH
[BBBBBBBB

The row with 4 bricks was left blank because you had less than 4 in your hand after putting down 8 of you original 11 blue bricks.

Then go down the row of blues, marking 1 if that row has blue bricks and zero if it doesn't

B
[ 1
[BB
[ 1
[
[0
[BBBBBBB

[0

CrotchetQuaverMinim Fri 01-Apr-16 22:35:57

We could work in base 12, for example, but we'd need two more symbols than we currently have (one would represent 10, and the other 11). Then when you get to twelve, you'd have to write 10 (meaning 1 lot of 12^1 = 12, and no lots of 12^0 =1).

Ramaani Fri 01-Apr-16 22:37:02

[B
[ 1
[BB
[ 1
[
[ 0
[BBBBBBBB
[1

(Typo)

So 11. In binary is 1101.

That's the same as saying 11= 1+2+8

megletthesecond Fri 01-Apr-16 22:40:04

I've just worked out my age in binary numbers and I am 101001 yrs old. <<swot>>

janethegirl2 Fri 01-Apr-16 22:41:20

11 is 1011

ILeaveTheRoomForTwoMinutes Fri 01-Apr-16 22:46:32

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