\fdO'^ - Old Forge Coal Mines

10 ARITHMETIC.
(70 X 50 X 24 X 20).
Placing the numerator over the denominator, the problem
becomes
(d) (80 X 60 X 50 X 16 X 14) -=-
80 X 60 X 50 X 16 X 14 ~ _ ^
'
70 X 50 X 24 X 20
The 50 in the dividctid and 70 in the divisor are both divis-
ible by 10, since 50 divided by 10 equals 5, and 70 divided
by 10 equals 7. Cross offxhe 50 and write the 5 over it;
also, cross off the 70 and write the 7 under it. Thus,
5
80 X 60 X ^P X 16 X 14 _
yp X 50 X 24 X 20
7
The 50 and 70 are not to be considered any longer, and;
in fact, may be erased entirely and the 5 and 7 placed in
their stead, and treated as if the 50 and 70 never existed.
Thus,
80 X 60 X 5 X 16 X 14 ~ _
7 X 50 X 24 X 20
Also, 80 in the dividend and 20 in the divisor are divisible
by 20, since 80 divided by 20 equals 4, and 20 divided by 20
equals 1. Cross off the 80 and write the 4 over it; also,
cross off the 20 and write the 1 under it. Thus,
4
^P X 60 X 5 X 16 X 14 ^
7 X 50 X 24 X ^P 1
The 80 and 20 are not to be considered any longer, and,
in fact, may be erased entirely and the 4 and 1 placed in
their stead, and treated as if the 80 and 20 never existed.
Thus,
4X 60X 5X 16 X 14 ^
7 X 50 X 24 X 1
Again, 16 in the dividend and 24 in the divisor are divisible
by 8, since 16 divided by 8 equals 2, and 24 divided by 8
equals 3. Cross off\.\\& 16 and write the 2 over it;
off the 24 and write the 3 under it. Thus,
also cross