2.3+5.4+8.7+3.6=( ◯ )◯( ◯ )
5.4+0.74+4.6=5.4++0.74
4.04+13.57+2.43=4.04+(◯)
48.72-0.2-0.8=48.72-(◯)
结论:
①8.47+12.53-1.2 ②50-19.8-20.2 ③19.4+4.58+5.42
100-24.58-35.42
76×98+152
2990÷13-2990÷23
25×16×125
158×[(27+54)÷9]
4.13-3.66+5.87-2.34
32+6.4+68+3.6 27+0.4-8.27 18.51-9.03-0.97