Math Is Fun Forum

booboo12

Member

Registered: 2006-07-11

Posts: 5

oooohhh...and..

Show me how or direct me to the page...

Divide 142.57 by .04 to the hundredths place

John E. Franklin

Member

Registered: 2005-08-29

Posts: 3,588

Re: oooohhh...and..

Divide 142.57 by .04
      __________
.04 )  142.57

Move decimal points over so .04 is 4

Move both #'s decimals points right by 2 spots.
   ________
4 ) 14257

Okay, 1 is less than 4, so start with 14

How many 4's fit into 14 ?
3, so answer starts with 3.
3 x 4 is 12, take 12 from 14, get 2, bring down the 2, making 22.

How many 4's go into 22 ?
5, so now answer goes 35... and more.
5x4 is 20, take 20 from 22, get 2, bring down 5, making 25.

How many 4's go into 25 ?
6, so answer goes 356 so far...
6x4 is 24, take 24 from 25, get 1, bring down the 7, making 17.

How many 4's go into 17 ?
4, so answer goes 3564 point something.  The decimal goes after 3564 because the decimal point goes after the end of the number 14257.00000
4x4 is 16, take 16 from 17, get 1, now bring down a zero because we are doing the zeros after the decimal until
we get sick of it or it runs dry with a perfect subtraction to zero because the 4 fits perfect into the number.
We'll see...

How many times does 4 go into 10 ?
2, so answer is so far 3564.2
2x4 is 8,  8 from 10 is 2, so bring down another zero, making 20.

How many times does 4 go into 20 ?
5, and it is perfect!! 5x4 is 20!!! So subtraction is perfect zero, so answer is exactly 3564.25

The 5 is in the hundredths place so we are done:  3564.25

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igloo myrtilles fourmis

Heldensheld

Member

Registered: 2006-07-01

Posts: 25

Re: oooohhh...and..

THe calculator says......3564.25.

numen

Member

Registered: 2006-05-03

Posts: 115

Re: oooohhh...and..

I've had a calculator that gave me the wrong answer once (for real! and I threw it away too!), so I don't always trust them
Learn the trick John described, sooner or later you'll be using it for polynomial division anyway

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Bang postponed. Not big enough. Reboot.