Katie wrote these steps to find the estimated difference between 69 and 31.

step 1: 69 rounded to the nearest ten is 70.
step 2: 31 rounded to the nearest ten is 40.
step 3: the term difference means "to subtract.”
step 4: the estimated difference between 69 and 31 is
70 – 40 = 30.

in what step did her first error occur?

step 1
step 2
step 3
step 4