Let the number of frogs in the Blue Pond be x
Blue Pond = x
There were 26 more frogs in Green Pond than in Blue Pond
Green Pond = x + 26
There were 80 frogs altogether
x + x + 26 = 80
2x + 26 = 80
2x = 80 - 26
2x = 54
x = 27
x + 26 = 27 + 26 = 53
There were 53 frogs in the Green Pond originally.