Whoa. I’m not very good with math, nor am I very good with children and remembering what grade they are in at what age, etc. I just learned this wicked easy way to know a kids age or in the inverse, their grade.
To find age (when grade is known)
Age = Grade + 5
To find grade (when age is known)
Grade = Age — 5
Now I won’t feel like an idiot asking about kids grades and age and such.