This year the fifth grade collected 216 fewer plastic containers than the fourth grade. How many plastic containers did the fifth grade collect

Let number of plastic containers collected by fourth grade = x

Then number of plastic containers collected by fifth grade students=x-216

OR

If number of plastic container collected by fifth grade is y

then number of plastic container collected by fourth grade=y+216

So, we can write it as follows

⇒ number of plastic containers collected by fourth grade = number of plastic containers collected by fifth grade + 216