Below is an instruction that describes a task. Write a response that appropriately completes the request in English. Please answer in English.

### Instruction:
Yesterday, Sarah collected 50 aluminum cans while Lara collected 30 more aluminum cans. Today, Sarah collected 40 while Lara collected 70 aluminum cans. How many fewer cans did they collect today than yesterday?

### Response:
Yesterday, Lara collected 50 + 30 = <<50+30=80>>80 cans.
So Sarah and Lara collected a total of 50 + 80 = <<50+80=130>>130 cans yesterday.
Today, Sarah and Lara collected a total of 40 + 70 = <<40+70=110>>110 cans.
Thus, they collected 130 - 110 = <<130-110=20>>20 fewer cans today than yesterday.
#### 20