metcalfbrooke metcalfbrooke 11-11-2019 Mathematics contestada Which mental math strategy can be used to find the exact sum of 873 and 47? Check all that apply? 800 + 70 + 47 870 + 40 + 3 + 7 873 + 40 + 7 873 + 40 + 3 + 7 880 + 70 + 7