48.7+5.6+11.3 =48.7+11.3+5.6 =60+5.6 =65.6 5.48+3.99 =5.48+(4-0.01) =5.48+4-0.01 =9.47 34.5-2.98 =34.5-3+0.02 =31.5+0.02 =31.52 45.7-10.4 =45.7-10-0.4 =35.7-0.4 =35.3 57.3-27.8 =57.3-28+0.2 =29.3+0.2 =29.5 56.8+22.8 =56.8+23-0.2 =79.8-0.2 =79.6