Math Worksheets

Archive for May, 2007

Question: math help! (four fours)?

okay so i have this math worksheet thats due in a few days and i’m almost done but i have a few problems that i absolutely CANNOT get. basicly, i have to come up with these equations using only the number four four times. for example:

[(4!+4)/4)]+4! is equal to 31

i cannot use decimals, combine numbers (like putting four and four together to make 44) or negative, however the equation may become negative temporarily. Radical symbols, factorials, exponents (but only four to the fourth) and parenthesies may be used.

the numbers i still need:
35
37
39
41
43
51
53
55
57
59
61
67
69
71
73
75
77
78
79
81
83
85
87
89
91
93
99

that’s out of 200 so i’m pretty much done. i would REALLY appreciate help.
oh yeah and you can only use simple operation symbols like +, -, x, and /

Answer: Given the restrictions you have, most if not all of those numbers
(they’re all odd, you’ll notice and many of them are prime)
cannot be done.

That means, if you have solved all the other numbers,
you have done a really great job!

Here’s a page with every number up to 100 solved —
but ….
most of the ones on your list use “44″ or “.4″ to get
some odd factors into the game.

If you can’t do that, I think you’re stuck.

Solutions to puzzle for 1 – 100:

http://mathforum.org/ruth/four4s.puzzle.html

.

Multiplying Decimals

Question: If your allowance was penny doubled everday, how many days would it take you in order to have over 1000.00?

I have to do this for a math worksheet and i kind of remember how to do it, i just need a little memory boost. The sequence would at first go like this
1,2,4,8,16,32,__
x*2(n-1)
Am i sing the right formula?

Answer: not sure what you Mean by “x*2(n-1)”

but the right formula is 2^(n-1)
where ^ is raising to a power

you would go: like this:
1
2
4
8
16
32
64
128
256
512
1024
2048
4096
8192
16384
32768
65536
131072 (on the 17th day after you started)

Finance in Excel 6 – Calculate Double Declining Balance Method of Depreciation in Excel