Making number sentence correct for instance 1/4 = / 8. How do you figure these kind of problem? 6/4=12/??

You look to see the change in the numerator or denominator and apply that to the part of the fraction you are looking for

for example 1/4=?/8

8/4 = 2

that means i have to multiply 2 times 1 to find the value of the numerator

the final answer is 1/4=2/8

6/4=12/?

12/6 = 2

4 times 2 = 8

the answer is 6/4=12/8

6/4=12/8

1/4=2/8

Now cross multiply to check answers. 6x8=48 and 4x12=48

1x8=8 and 4x2=8