When comparing twenty-three forty-seconds to one-half using mental math, what fraction is useful?

twenty-three halves

twenty-three twenty-firsts

twenty-one forty-seconds

twenty-three forty-sixths

Question

When comparing twenty-three forty-seconds to one-half using mental math, what fraction is useful? 

 twenty-three halves 

 twenty-three twenty-firsts 

 twenty-one forty-seconds 

 twenty-three forty-sixths

anonymous · Answer

pleas help me

anonymous · Answer

To compare 23 / 42 to 1/2, make the denominator the same. by multiplying top and bottom of 1/2 by 21.  1/2 = 21/42.  It is now easier to compare 23/42 and 21/42.
Both denominators are the same and therefore 23/42 is greater than 21/42 or 1/2.