math question thing............?

Question

6lb. 8oz.
- 4lb. 9oz.



yeah im not good at that whole converting thing and im helping my little sister so yeah and please dont put anything like "she can do her own homework" ok or else i will report abuse

Answer 1

Convert 6 lb 8 oz to 5 lb 24 oz.
This is a problem with our system of measurements based on multiples of 16, 12, etc, rather than 10. If it were all based on 10 you could just subtract like usual, and "borrow" from the next decimal place. But as it is, you have to think of it like this:
Since there are 16 oz to the lb...

(6 8/16) - (4 9/16) = (5 + 1 + 8/16) - (4 9/16) = (5 + 16/16 + 8/16) - (4 9/16) = (5 24/16) - (4 9/16) = 1 15/16 = 1 lb 15 oz
or you could do it like the other guy said.

This is really a matter of subtracting fractions and mixed numbers. Let's see if I can find you a good online explanation of subtracting fractions and mixed numbers. (BTW, for an online tutorial on just about anything, put subject tutorial in your search window. For example, I'm putting subtract fractions mixed numbers tutorial in the seach window now...
http://www.math.com/school/subject1/lessons/S1U4L6GL.html
http://www.wtamu.edu/academic/anns/mps/math/mathlab/beg_algebra/beg_alg_tut3_fractions.htm
http://www.visualfractions.com/
http://www.kidsolr.com/math/fractions.html

Answer 2

You do this the way you were always taught to do subtraction, but with a slight wrinkle. Suppose the problem were:

68
- 49
-------

What would you do? You would "borrow" 1 "ten" from the ten's place and add it to the units place, then do the subtraction. Like so

5 (18)
- 4 9
----------
1 9 or 19

Now, do the same thing, but this time you are borrowing 1 lbs from the pound's colum and addin that to the ounces column. The wrinkle? How many ounces in a pound (not 10!). Yes, of course, 16 ounces in a pound. So, you do this

5 (24)
- 4 ( 9)
------------
1 15 or 1 lbs 15 oz.

It is what you have always done, just in pounds and ounces rather than 10's and units.

HTH

Charles

Answer 3

No need to convert, though it may help, depending on your style. Simply subtract 4 from 6, and get 2 pounds. Then, subtract 9 from 8 and get -1 ounces. Knowing that there are 16 ounces in a pound, you can reason that 2 pounds and -1 ounces is really 1 pound and 15 ounces.

Answer 4

add 16 oz to the 8 oz, and that takes away 16 oz (aka 1 lb) from the 6 lb.

6 lb 8 oz
-
4 lb 9 oz =

5 lb 24 oz
-
4 lb 9 oz
---------------
1 lb 15 oz

Answer 5

1lb=16oz
(16*6+8)-(16*4+9)
(96+8)-(64+9)
104-73
37oz
divide 37/16
2lb 5oz

Answer 6

5lbs.24oz
_ 4lbs. 9oz
_______________
1lb.15oz