# use only four 4's to make 10

Show 40 post(s) from this thread on one page
Page 1 of 2 12 Last
• September 3rd 2008, 02:34 PM
darryl950
use only four 4's to make 10
hi its my second day at high school and they given me homework due in tomorrow morning plz help

ive got to get four 4's into 10

for example if i had to get four 4's into 8 i could do

4 x 4 -4-4 = 8
can use no other numbers but 4 and only 4 times

for the number 7 i got 4 + 4 - (4/4) = 7

plz help !!
very grateful ty
• September 3rd 2008, 03:10 PM
Maths_Tutoring
((4+4)/4) + (4+4) = 2 + 8
• September 3rd 2008, 03:13 PM
particlejohn
Quote:

Originally Posted by Maths_Tutoring
((4+4)/4) + (4+4) = 2 + 8

Thats five fours.
• September 3rd 2008, 03:13 PM
darryl950
thats 5
• September 3rd 2008, 03:13 PM
i thot he said four 4s?

im counting 5 :D

are you sure theres no other things we can use besides +- /*?
• September 3rd 2008, 03:14 PM
darryl950
u can use any simbols
but only 4 4's
no other numbers no less and no more than 4 4's
• September 3rd 2008, 03:16 PM
4*4 -4 - sqrt(4)
• September 3rd 2008, 03:17 PM
darryl950
only onther way to do it i guess didnt really wanna use square root
not sur eif teACHEr will accept, i got 4 + sqr 4 +sqr 4 +sqrt4

thanks for d help guyz
• September 3rd 2008, 03:20 PM
Chris L T521
Quote:

4*4 -4 - sqrt(4)

If it was in exponential format, we'd have $4*4-4-(4)^{1/2}$, which introduces a 2 that we don't want.

If we were to just use symbols, your way is good. [Assuming that $\sqrt{4}>0\implies \sqrt{4}=2~and~not~\pm2$]

--Chris
• September 3rd 2008, 03:22 PM
aahhhh bustin mah chops :D

i cant see any other way...
• September 3rd 2008, 03:30 PM
Maths_Tutoring
eeepps, I thought this was just asking for fours not four fours! a little tricker than I first thought, will have to have a re-think
yup, with out using sqrts it's a toughy, since it really only leaves you with a few options to play with

4! = 24
4toThe4 = 256
4*4 = 16
4+4 = 8
• September 3rd 2008, 03:57 PM
skeeter
$\frac{44-4}{4}$
• September 4th 2008, 12:30 AM
Moo
Quote:

Originally Posted by Chris L T521
$\sqrt{4}>0\implies \sqrt{4}=2~and~not~\pm2$]

--Chris

$\sqrt{4}$ EQUALS 2, there's no question about it !
• September 4th 2008, 12:45 AM
Chop Suey
Quote:

Originally Posted by Moo
$\sqrt{4}$ EQUALS 2, there's no question about it !

What he meant that this doesn't fit the requirements of four 4's. There will be a $\frac{1}{2}$, should it be written as an exponent.
• September 4th 2008, 08:42 AM
Kai
Quote:

Originally Posted by skeeter
$\frac{44-4}{4}$

Ermm, can 44 really be counted as 2 fours ??, i mean theres no operation relating 44 and 2 fours, not really sure about it
Show 40 post(s) from this thread on one page
Page 1 of 2 12 Last