40 Divided By 4.5 = ?

[Into the Light]

40/4.5 = 8.89 to 2 decimal places but how would i work this out without a calculator???

normally you just move the deciaml across till the number becomes a whole integer. So in this case you times both 4.5 and 40 by 10 to make it easier to work with right???? ie 400/45

so 400/45 is 8 remainder 40

...but then how do you work out 40/45???

i need to know how to work the answer out to 2 decimal places on paper without a calculator

i hope this makes sense...i know it sounds easy or maybe it is and i'm just thick

PLZZZ HELP!!!!!

behnti to admins pls keep this in General section till tommorrow night as i need help and this is where most people browse

[Revolutionary]

basicaly u just worked it out..

normally you just move the deciaml across till the number becomes a whole integer. So in this case you times both 4.5 and 40 by 10 to make it easier to work with right???? ie 400/45

so 400/45 is 8 remainder 40

...but then how do you work out 40/45???

well u do what u just did... (40/4.5 was ur original question .. 40/45 is that answer divided by 10 ie: 0.8 instead of 8)

0.8 x 45 = 36... so remainder is 4.. 4/45 = 0.08... then 0.4/45 etc...

so the answer will be 8.88888888888...

round it up tio 2 decimal points... 8.89

[Into the Light]

sorry bhaji/bhenji, i didn't get that

basically i'm trying to work out how to divde by decimals

lets try another one..maybe it might click to me with another example

so if we did 7/2.9 = 2.41 (2 decimal points)

[Revolutionary]

so thats.. 70/29 = 2 remainder 12. so then its 12/29..yaar thats too hard can't u just get away with 2 and 12 29ths..?

[Singh, Mahan]

.

First take 40/4.5

400/45

= 8 + 40/45 (Now the remainder written as (400/45)/10 )

= 8+0.8+ (400/45)/100 = 8+0.8+0.08 ( 8 will keep recurring )

So, 40/4.5= 8.888888888888

Now take 70/29

70/29

= 2+12/29 = 2+ (120/29)/10

=2+0.4 + the remainder is (4/29)/10 which is (40/29)100

=2+0.4+0.01 +the remainder is (11/29)/100 which is (110/29)/1000

=2+0.4+0.01+0.003 + the remainder is (23/29)/1000 which is (230/29)/10000

=2.413+(230/29)/10000

=2.413 + 0.0007 + the remainder is (27/29)/10000 [ let us close at four decimal places].

= 2.4137 ( However the remainder, by visual inspection would be 0.00009 + )

= 2.41379

One can do these numbers to what is called 4 significant digits in HEAD. In both these examples the answer being under 10, the four significant digits means up to 3 decimal places.

So

40/4.5= 8.888 (approximately = 8.889)

70/29 = 2.413 (approximately = 2.414)

( Four significant digit means that there are only four digits in the answer. the decimal point is not considered as a digit)

[ocelot]

I will try to simplify it 40 / 4.5 to 80/9 and then solve. that is to change denominator to full. it can be then solved orally 8.888 .Just give it a try. Fractions are easy.

[Into the Light]

thank you all

:WW:

[Surban]

I will try to simplify it 40 / 4.5 to 80/9 and then solve. that is to change denominator to full. it can be then solved orally 8.888 .Just give it a try. Fractions are easy.

hmm ya or u cud tak 40/4.5 = 40/(9/2) = 40*(2/9) = 40*(1/4.5)

k u no (1/5) = 0.20 and (1/4) = 0.25 so (1/4.5) has to equal roughly 0.222

so its 40*(0.222).. so whts 22.2% of 40??

well first whts 1% of 40?.. its 0.40 (cause 1%=(1/100) so 40*(1/100) = 40/100 = .40)

so now whts 0.2% of 40? = 0.08 (cause 0.2%=[(1/5)/100] so 40*(1/500) = 40/500 = 8/100(divided top an bottom by 5) = 0.08)

k now 20% of 40 is 8 so 22.2% of 40 has to be (20%+1%+1%+0.2%) 8+0.40+0.40+0.08 = 8.88

:lol: lol... hope all tht made sence

[ocelot]

I will try to simplify it 40 / 4.5 to 80/9 and then solve. that is to change denominator to full. it can be then solved orally 8.888 .Just give it a try. Fractions are easy.

hmm ya or u cud tak 40/4.5 = 40/(9/2) = 40*(2/9) = 40*(1/4.5)

k u no (1/5) = 0.20 and (1/4) = 0.25 so (1/4.5) has to equal roughly 0.222

so its 40*(0.222).. so whts 22.2% of 40??

well first whts 1% of 40?.. its 0.40 (cause 1%=(1/100) so 40*(1/100) = 40/100 = .40)

so now whts 0.2% of 40? = 0.08 (cause 0.2%=[(1/5)/100] so 40*(1/500) = 40/500 = 8/100(divided top an bottom by 5) = 0.08)

k now 20% of 40 is 8 so 22.5% of 40 has to be (20%+1%+1%+0.2%) 8+0.40+0.40+0.08 = 8.88

:lol: lol... hope all tht made sence

My method was not that bad

I really use it in many cases.

But your work rocks.