有括号,先算括号。本题可将括号拿掉。则原本里面的减号,会变成加号。
其中,7.23可以分成7+0.23
9.65-7.23+0.35
=9.65+0.35-7.23
=10-7.23
=10-(7+0.23)
=10-7-0.23
=3-0.23
=2.77
9.65-(7.23-0.35)
=9.65-7.23+0.35
=9.65+0.35-7.23
=10-7.23
=2.77
3.4+13.7+8.5
=17.1+8.5
=25.6
15-(3.2+4.9)
=15-8.1
=6.9
8.76-1.23-0.77
=8.76-(1.23+0.77)
=8.76-2
=6.76
9.65-(7.23-0.35)
=9.65+0.35-7.23
=10-7.23
=2.77