To add fractions, they need to have the same, common denominator. In this case, the common denominator would be 16.
You want to make sure all parts have 16 as the denominator.
In #1/4#, we have to multiply both top and bottom by a same number to get the denominator as 16. The number in this case is 4 #(4*4=16)#
#(1/4)*(4/4)=(4/16)#
We don't have to change#1/16# and #5/16# since their denominator is already 16.
In #3/8#, we need to multiply the numerator and denominator to get the denominator as 16. The number in this case is 2 #(8*2=16)#
#(3/8)*(2/2)=(6/16)#
Now if we put it together, we get #(4/16)+(1/16)+(5/16)+(6/16)# and since they have the common denominator, you can just add the numerators together to find the answer.
#(4+1+5+6)/16 = 16/16 = 1 #
