Jump to content
Science Forums

Want to learn basic maths


Recommended Posts

  • 1 month later...

i can't think of anything more basic than khan academy.

never the less here is my vain attempt

 

numbers

here i show all numbers between 1 and 9.

if i want to add one more, i need one more symbol for the empty case, 0.

when you add 1 to 9, the basket on the left, empty, gets a dot, or 1, and the basket with 9 gets to be 0.

so 10 is equal to ten ones.

so if i want to add two numbers, here's several examples.

17 +14 = so starting on the right, 7 +4 = 11, that is, 1 ten, and 1 one, the 1 ten gets carried over, and i  have 1+1+1, = 30

so 3 for the tens place, and 1 for the ones place, gives me a total of 31.

here's another example, 25 +39. again start by adding the right hand side. 5+9 = 14, and then 1+2+3 = 6, giving me 64.

one more.

67 +22.  7+2 = 9, 6+2 = 8, there fore, 89.

there are numbers higher than ten of course, 100 is the next place 1 over, or 10 tens.

add them in the same way.

145 + 173 = 5+3 = 8, 4+7 = 11, 1+1+1 = 3, thus 318. or three hundred and eighteen.

and there is no upper limit on how many places you can have. thousands, 10 thousands, 100 thousands, millions etc.

let me know if all this makes sense. then I'll go into subtraction.

 

 

Link to post
Share on other sites
15 minutes ago, write4u said:

should 67+22 = be entered as 6+2 and 7+2 = 89 in that order? The way you posted 7+2 and 6+2 (in that order) would result in 98 ?

I think he means that if you put the 67 over the 22 vertically you would first add the 7+2 in the ones column, in order to carry any over to the tens column if need be. In this case it doesn't matter because it's only 9, so no need to carry the 1 in this case. So he's working from right to left, or ones to tens when he says 7+2 and then 6+2. He is correct. The 7+2 is the ones, and the 6+2 is the tens, so 8 tens and 9 ones, or 89.

Edited by Motor Daddy
Link to post
Share on other sites
17 hours ago, phillip1882 said:

and there is no upper limit on how many places you can have. thousands, 10 thousands, 100 thousands, millions etc.

let me know if all this makes sense. then I'll go into subtraction.

There is also what is after the decimal point, which is the fractional part of the decimal number.

Example is 1.125

That is 1 one, and 125 Thousandths.

Example 1.05 is 1 one and 5 Hundredths

 

.009 is 9 Thousandths, or 9/1000

.012 is 12 Thousandths, or 12/1000

.0033 is 33 Ten Thousandths, or 33/10,000

.5 is 5/10, reduces to 1/2

.25 is 25/100 reduces to 1/4

.20 is 20/100 reduces to 1/5

.125 is 125/1000 reduces to 1/8

.10 is 10/100 reduces to 1/10

.05 is 5/100 reduces to 1/20

.375 is 375/1000 reduces to 3/8

.625 is 625/1000 reduces to 5/8

.750 is 750/1000 reduces to 3/4

.03125 is 3,125/100,000 reduces to 1/32

.03125 x 32 = 1.0

.03125 x 11 = .34375 or 34,375/100,000 reduces to 11/32

1 divided by 64 = .015625, or 1/64, so .015625 x 64 = 1.0

.015625 x 11 = .171875, or 171,875/1,000,000 reduces to 11/64

1.0 is 1 one, or 10 Tenths, or 100 Hundredths, or 10/10, or 100/100

1.1 is 11 Tenths or 11/10

1.11 is 111 Hundredths, or 11.1 Tenths, 11.1/10 😉

.25 + .25 = .5, or 50/100 reduces to 5/10, or 1/4+1/4=2/4=1/2

.5+.5=1.0, or 5/10+5/10=10/10=1.0, or 1/2+1/2=2/2=1.0, or 2 halfs equal 1 whole.

Edited by Motor Daddy
Link to post
Share on other sites
3 hours ago, Motor Daddy said:

He is correct. The 7+2 is the ones, and the 6+2 is the tens, so 8 tens and 9 ones, or 89.

Simple vertical addition! Thanks for that explanation.  Makes sense now.

Edited by write4u
Link to post
Share on other sites

Thanks for all the replies ,

I have few more dumb questions ...

I have learned this much myself , i wish there was one book that explains it all , but i cant find that one book that explains everything like this ,

[img]https://i.ibb.co/YTz3cFv/Untitled.png[/img]

I know by now that we need to find lcm for fractions ,

But where do we use the gcf for ?

 

 

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...