Elena used math facts as an anchor to find the sum of 5 and
7. her work is shown.
in which step did her first error occur?
step 1: the phrase "sum of means addition,
step 2: 5 + 5 = 10
step 3: since 7 is 2 more than 5, 2 more need to be added to
10.
step 4: therefore, 5+ 7 = 8.
step 1
step 2
step 3
step 4