We have a total of 178 6th and 7th graders. And we are informed that there are 12 more 6th graders the 7th graders. Let x = the number of 7th graders
x + (x + 12) = 178
Subtract 12 from both sides
x + x = 166
Add like terms
2x = 166
x = 83
So, there are 83 7th graders. And add 12 to find the number of 6th graders.
12 + 83 = 95
