脱式计算按照先乘除后加减,先括号里后括号外的的原则,例如:
1.
4×102-2×49
=408-2×49
=408-98
=310
2.
25×(2+4)
=25×2+25×4
=50+100
=150
3.
12×5+8
=60+8
=68
4.
99×101
=99×(100+1)
=99×100+99×1
=9900+99
=9999
5.
25×(78×4)
=25×4×78
=100×78
=7800
6.
(25+12)×4
=25×4+12×4
=100+48
=148
7.
1.4+0.7+8.6
=(1.4+8.6)+0.7
=10+0.7
=10.7
8.
56×27+27×44
=27×(56+44)
=27×100
=2700
9.
56×99+56
=56×(99+1)
=56×100
=5600
10.
125×25×8×4
=(25×4)×(125×8)
=100×1000
=100000
12.
25×125×4
=(25×4)×125
=100×125
=12500
13.
125×47-47×25
=47×(125-25)
=47×100
=4700
14.
124×38+65×124+76×110-76×7
=124×(38+65)+76×(110-7)
=124×103+76×103
=103×(124+76)
=103×200
=20600
15.
233-157-43
=233-(157+43)
=233-200
=33
16.
125×32×25
=125×8×4×25
=(125×8)×(4×25)
=1000×100
=100000
17.
1.25×(8+10)
=125×8+125×10
=1000+1250
=2250
18.
99+99×99
=99×(99+1)
=99×100
=9900
19.
264×97+3×264
=264×(97+3)
=264×100
=26400
20.
62×4+44×6+6×18
=62×4+6×(44+18)
=62×4+6×62
=62×(4+6)
=62×10
=62
21
55+60+40+45
=(55+45)+(60+40)
=100+100
=200
22
1. 6÷ 3/8 – 3/8 ÷6
=1/6x(3/8-3/8)
=1/6x0
=0
23. 4/7 × 5/9 + 3/7 × 5/9
=(4/7+3/7)x5/9
=1x5/9
=5/9
24. 5/2 -( 3/2 + 4/5 )
=5/2-3/2-4/5
=1-4/5
=1/5
25. 6 ×( 1/2 + 2/3 )
=6x1/2+6x2/3
=3+4
=7
26. 8 × 4/5 + 8 × 11/5
=8x(4/5+11/5)
=8x3
=24
27. 31 × 5/6 – 5/6
=(31-1)x5/6
=30x5/6
=25
28. 4/5 × 25/16 + 2/3 × 3/4
=5/4+1/2
=5/4+2/4
=7/4
29
101 × 1/5 – 1/5 × 21
=(101-21)x1/5
=80x1/5
=16