Change the words "a number" by N

Twice N divided by 4 is 16

Cange the words "N divided by 4" to 

Twice  is 16

Change the word "Twice" to "2 times"

2 times  is 16

Replace the word "times" with "*"

2* is 16

Replace "2*" by 

 is 16

Replace the word "is" by " = "



Multiply both sides by 4:






 
Divide both sides by 2







Edwin