Divide the amount of burger meat by the number of burgers he wants to make:
6 1/4 pounds of burger meat
10 burger
Express the mixed number as a fraction:
6 1/4 = (6x4+1)/4 = 25/4
Now, divide:
To divide fractions multiply by the reciprocal of the second term
25/4 x 1/10 = 25/40 = 5/8 meat per burger