At Kids College, 5 times as many children signed up for writing as math. If 18 children switch from writing to math, there will be an equal number of children in each class. How many children are there altogether?
Let the number of children signed up for math==M
THen, the number of children who signed up for writing==5M
5M - 18 ==M + 18, solve for M
5M - M == 18 + 18
4M == 36
M ==36 / 4
M ==9 - number of children who signed up for math
5 * 9 ==45 children who signed up for writing
9 + 45 ==54 total number of students.