Keith brought a package with 2 9/16 pound of of ground meat to make hamburgers. he has 2/5 pound of ground meat left. about how many pounds of ground meat did he use for the hamburgers?

First convert the mixed number into an improper fraction.

41/16 is the total.
Keith has 2/5 pounds left.
Now, find a common factor between 16 and 5. It is 80
Multiply 41*5 and 16*5 and you will get 205/80.
Now multiply 2*16 and 5*16 to get 32/80.
Next, subtract. 205/80 minus 32/80 which gives you 173/80
Lastly simplify. 2 13/80 is the amount of meat he used.