Lian was asked to write an equation and solve this problem.

Shonda has some small spoons and 40 large spoons. If she has 68 spoons total, how many small spoons does Shonda have?

Lian’s work is shown below.

Steps
Lian’s Work
Step 1
s + 40 = 68
Step 2
s + 40 minus 40 = 68 minus 40
Step 3
s = 28

In which step, if any, did Lian first make a mistake in her work?
step 1
step 2
step 3
no mistake