（720+270）÷55-120÷24
=990÷55-120÷(12×2)
=990÷110×2-120÷12÷2
=9×2-10÷2
=18-5
=13
（63+480÷16）-29
=（63+30×16÷16）-29
=63+30-30+1
=64
13.67-2.97+25.8
=13.67-3+0.03+25.8
=10.67+0.03+25.8
=10.7+25.8
=36.5
7.06-2.78+13.78
=7.06+13.78-2.78
=7.06-（13.78-2.78）
=7.06+11
=18.06
0.64×25×7.8+2.2
=0.16*4*25*7.8+2.2
=0.16*100*7.8+2.2
=16*7.8+2.2
=127
2÷2.5+2.5÷2
=4/5+5/4
=2.05
194－64.8÷1.8×0.9
=194-36*0.9
=194-32.4
=161.6
36.72÷4.25×9.9
=8.64*9.9
=85.536
5180－705×6
=5180-4230
=950
24÷2.4－2.5×0.8
=10-2
=8
(4121+2389)÷7
=6510/7
=930
671×15-974
=10065-974
=9091
469×12+1492
=5628+1492
=7120
405×(3213-3189)
=405*24
=9720
1）、0.36x1.5x0.4=0.4x5x0.36x0.3=2x0.108=0.216
2)、0.05x3.2x40=0.05x40x3.2=2x3.2=6.4
3)、3.78x0.5-0.65=3.78x0.5-1.3x0.5=(3.78-1.3)x0.5=2.48x0.5=1.24
4)、13.4x0.24+3.98=13.4x0.6x0.4+3.98=8.04x0.4+3.98=3.216+3.98=7.196
5)、3.8x41-3.8=3.8x(41-1)=3.8x40=152
6)、0.3x2.5x0.4=0.3x1=0.3
7)、0.78x101=0.78x100+0.78x1=78+0.78=78.78
8)、1.2x2.5+0.8x2.5=(1.2+0.8)x2.5=2x2.5=5
9)、9.8x25=10x25-0.2x25=250-5=245
10)、0.8x630x0.125=0.8x0.125x630=0.1x630=63
11)、198x0.51=200x0.51-2x0.51=102-1.02=100.98
12)、2.5x3.7+6.3x2.5=(3.7+6.3)x2.5=10x2.5=25
(45-17)+(9-3)=28+6=34,
(45-17)+(9-6)=28+3=31,
(45-18)+(9-3)=27+6=33
(45-18)+(9-6)=27+3=30,
(45-27)+(9-3)=18+6=24,
(45-27)+(9-6)=18+3=21
(45-28)+(9-3)=17+6=23,
(45-28)+(9-6)=17+3=20,
(46-17)+(8-3)=29+5=34
(46-17)+(8-5)=29+3=32,
(46-19)+(8-3)=27+5=32,
(46-19)+(8-5)=27+3=30
(46-27)+(8-3)=19+5=24,
(46-27)+(8-5)=19+3=22,
(46-29)+(8-3)=17+5=22
(46-29)+(8-5)=17+3=20,
(54-16)+(9-2)=38+7=45,
(54-16)+(9-7)=38+2=40
(54-18)+(9-2)=36+7=43,
(54-18)+(9-7)=36+2=38,
(54-36)+(9-2)=18+7=25
(54-36)+(9-7)=18+2=20,
(54-38)+(9-2)=16+7=23,
(54-38)+(9-7)=16+2=18
(57-18)+(6-2)=39+4=43,
(57-18)+(6-4)=39+2=41,
(57-19)+(6-2)=38+4=42
(57-19)+(6-4)=38+2=40,
(57-38)+(6-2)=19+4=23,
(57-38)+(6-4)=19+2=21
(57-39)+(6-2)=18+4=22,
(57-39)+(6-4)=18+2=20,
(63-15)+(9-2)=48+7=55
(63-15)+(9-7)=48+2=50,
(63-18)+(9-2)=45+7=52,
(63-18)+(9-7)=45+2=47
(63-45)+(9-2)=18+7=25,
(63-45)+(9-7)=18+2=20,
(63-48)+(9-2)=15+7=22
(63-48)+(9-7)=15+2=17,
(64-25)+(8-1)=39+7=46,
(64-25)+(8-7)=39+1=40
(64-29)+(8-1)=35+7=42,
(64-29)+(8-7)=35+1=36,
(64-35)+(8-1)=29+7=36
(64-35)+(8-7)=29+1=30,
(64-39)+(8-1)=25+7=32,
(64-39)+(8-7)=25+1=26
(67-18)+(5-2)=49+3=52,
(67-18)+(5-3)=49+2=51,
(67-19)+(5-2)=48+3=51
(67-19)+(5-3)=48+2=50,
(67-28)+(5-1)=39+4=43,
(67-28)+(5-4)=39+1=40
(67-29)+(5-1)=38+4=42,
(67-29)+(5-4)=38+1=39,
(67-38)+(5-1)=29+4=33
(67-38)+(5-4)=29+1=30,
(67-39)+(5-1)=28+4=32,
(67-39)+(5-4)=28+1=29
(67-48)+(5-2)=19+3=22,
(67-48)+(5-3)=19+2=21,
(67-49)+(5-2)=18+3=21
(67-49)+(5-3)=18+2=20,
(72-14)+(9-3)=58+6=64,
(72-14)+(9-6)=58+3=61
(72-18)+(9-3)=54+6=60,
(72-18)+(9-6)=54+3=57,
(72-54)+(9-3)=18+6=24
(72-54)+(9-6)=18+3=21,
(72-58)+(9-3)=14+6=20,
(72-58)+(9-6)=14+3=17
(73-14)+(8-2)=59+6=65,
(73-14)+(8-6)=59+2=61,
(73-19)+(8-2)=54+6=60
(73-19)+(8-6)=54+2=56,
(73-54)+(8-2)=19+6=25,
(73-54)+(8-6)=19+2=21
(73-59)+(8-2)=14+6=20,
(73-59)+(8-6)=14+2=16,
(81-24)+(9-3)=57+6=63
(81-24)+(9-6)=57+3=60,
(81-27)+(9-3)=54+6=60,
(81-27)+(9-6)=54+3=57
(81-35)+(9-2)=46+7=53,
(81-35)+(9-7)=46+2=48,
(81-36)+(9-2)=45+7=52
(81-36)+(9-7)=45+2=47,
(81-45)+(9-2)=36+7=43,
(81-45)+(9-7)=36+2=38
(81-46)+(9-2)=35+7=42,
(81-46)+(9-7)=35+2=37,
(81-54)+(9-3)=27+6=33
(81-54)+(9-6)=27+3=30,
(81-57)+(9-3)=24+6=30,
(81-57)+(9-6)=24+3=27
(83-14)+(7-2)=69+5=74,
(83-14)+(7-5)=69+2=71,
(83-19)+(7-2)=64+5=69
(83-19)+(7-5)=64+2=66,
(83-24)+(7-1)=59+6=65,
(83-24)+(7-6)=59+1=60
(83-29)+(7-1)=54+6=60,
(83-29)+(7-6)=54+1=55,
(83-54)+(7-1)=29+6=35
(83-54)+(7-6)=29+1=30,
(83-59)+(7-1)=24+6=30,
(83-59)+(7-6)=24+1=25
(83-64)+(7-2)=19+5=24,
(83-64)+(7-5)=19+2=21,
(83-69)+(7-2)=14+5=19
(83-69)+(7-5)=14+2=16,
(86-27)+(4-1)=59+3=62,
(86-27)+(4-3)=59+1=60
(86-29)+(4-1)=57+3=60,
(86-29)+(4-3)=57+1=58,
(86-57)+(4-1)=29+3=32
(86-57)+(4-3)=29+1=30,
(86-59)+(4-1)=27+3=30,
(86-59)+(4-3)=27+1=28
(91-24)+(8-3)=67+5=72,
(91-24)+(8-5)=67+3=70,
(91-27)+(8-3)=64+5=69
(91-27)+(8-5)=64+3=67,
(91-34)+(8-2)=57+6=63,
(91-34)+(8-6)=57+2=59
(91-37)+(8-2)=54+6=60,
(91-37)+(8-6)=54+2=56,
(91-54)+(8-2)=37+6=43
(91-54)+(8-6)=37+2=39,
(91-57)+(8-2)=34+6=40,
(91-57)+(8-6)=34+2=36
(91-64)+(8-3)=27+5=32,
(91-64)+(8-5)=27+3=30,
(91-67)+(8-3)=24+5=29
(91-67)+(8-5)=24+3=27,
(92-34)+(7-1)=58+6=64,
(92-34)+(7-6)=58+1=59
(92-38)+(7-1)=54+6=60,
(92-38)+(7-6)=54+1=55,
(92-54)+(7-1)=38+6=44
(92-54)+(7-6)=38+1=39,
(92-58)+(7-1)=34+6=40,
(92-58)+(7-6)=34+1=35
(93-15)+(6-2)=78+4=82,
(93-15)+(6-4)=78+2=80,
(93-18)+(6-2)=75+4=79
(93-18)+(6-4)=75+2=77,
(93-75)+(6-2)=18+4=22,
(93-75)+(6-4)=18+2=20
(93-78)+(6-2)=15+4=19,
(93-78)+(6-4)=15+2=17,
(94-16)+(5-2)=78+3=81
(94-16)+(5-3)=78+2=80,
(94-18)+(5-2)=76+3=79,
(94-18)+(5-3)=76+2=78
(94-76)+(5-2)=18+3=21,
(94-76)+(5-3)=18+2=20,
(94-78)+(5-2)=16+3=19
(94-78)+(5-3)=16+2=18,
(95-27)+(4-1)=68+3=71,
(95-27)+(4-3)=68+1=69
(95-28)+(4-1)=67+3=70,
(95-28)+(4-3)=67+1=68,
(95-67)+(4-1)=28+3=31
(95-67)+(4-3)=28+1=29,
(95-68)+(4-1)=27+3=30,
(95-68)+(4-3)=27+1=28