Simple calculation of decimals

Simple calculation of decimals


Simple operation of integers can also be applied to decimals (knowledge of grade 5)
Multiplicative Association Law: a * (b * c) = (a * b) * C
Commutative law of multiplication: a * b = b * a
Multiplicative distribution law: a * B + A * C = a * (B + C)
Additive commutative law: a + B = B + C
Additive combination law: a + (B + C) = (a + b) + C
The operational properties of subtraction: a-b-c = a - (B + C); a * B-A * C = a * (B + C); a * B-A * C = a * (B + C);
Operational properties of division: A / B / C = A / (b * c)
……
If you want to multiply decimals by decimals, I'll give you some examples.. 1) 2.8 × 1.5 = 1.4 × 3 = 4.2, which is a kind of more intuitive and simple calculation method
(7.2×4.5×8.1)÷(1.8×1.5×2.7)
=7.2×4.5×8.1÷1.8÷1.5÷2.7
=(7.2÷1.8)×(4.5÷1.5)×(8.1÷2.7)
=4×3×3
=4×9
=36
8.7-8.5+8.3-8.1+7.9-7.7+7.5-7.3+7.1-6.9
={(8.7+8.3)+(7.9+7.1)+7.5}-{(8.1+6.9)+(7.7+7.3)+8.5}=1
A simple algorithm is to add or subtract the results to get two integers



250 oral arithmetic questions about multiplication and division of decimals
There's only one day left


Please give 2 ~ 4 examples first



There must be an answer, the answer at the end of page 22,
Correct, incorrect, no, it's over page 25 now


Film 41: 1.45:12.63:13.2:1
4.3:25.3:16.10 and 2:17.2:18.1 and 4:39.15 and 10:1
10.2 and 1 in 8 11.13 and 5 in 7



3.2*10%=、50/1=、1+12%=、8/5-37.5%=、1.6/40%=、0.16*10%*100=
To write the calculation process, the second one is 50 / 1%


=3.2*0.1
=0.32
=50/0.01
=5000
=1+0.12
=1.12
=8 / 5-0.375
=1.6-0.375
=1.225
=1.6 / 0.1
=4
=0.16*0.1*100
=0.016*100
=1.6



More oral arithmetic. Percentages, decimals and fractions are OK. More fractions



3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17= 32.8+19= 5.2÷1.3= 1.6×0.4=
4.9×0.7= 1÷5= 6÷12= 0.87-0.49=
17×40= 100-63= 3.2+1.68= 2.8×0.4=
14-7.4= 1.92÷0.04= 0.32×500= 0.65+4.35=
10-5.4= 4÷20= 3.5×200= 1.5-0.06=
0.75÷15= 0.4×0.8= 4×0.25= 0.36+1.54=
1.01×99= 420÷35= 25×12= 135÷0.5=
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17= 32.8+19= 5.2÷1.3= 1.6×0.4=
4.9×0.7= 1÷5= 6÷12= 0.87-0.49=
17×40= 100-63= 3.2+1.68= 2.8×0.4=
14-7.4= 1.92÷0.04= 0.32×500= 0.65+4.35=
10-5.4= 4÷20= 3.5×200= 1.5-0.06=
0.75÷15= 0.4×0.8= 4×0.25= 0.36+1.54=
1.01×99= 420÷35= 25×12= 135÷0.5=
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17= 32.8+19= 5.2÷1.3= 1.6×0.4=
4.9×0.7= 1÷5= 6÷12= 0.87-0.49=
17×40= 100-63= 3.2+1.68= 2.8×0.4=
14-7.4= 1.92÷0.04= 0.32×500= 0.65+4.35=
10-5.4= 4÷20= 3.5×200= 1.5-0.06=
0.75÷15= 0.4×0.8= 4×0.25= 0.36+1.54=
1.01×99= 420÷35= 25×12= 135÷0.5=
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17= 32.8+19= 5.2÷1.3= 1.6×0.4=
4.9×0.7= 1÷5= 6÷12= 0.87-0.49=
17×40= 100-63= 3.2+1.68= 2.8×0.4=
14-7.4= 1.92÷0.04= 0.32×500= 0.65+4.35=
10-5.4= 4÷20= 3.5×200= 1.5-0.06=
0.75÷15= 0.4×0.8= 4×0.25= 0.36+1.54=
1.01×99= 420÷35= 25×12= 135÷0.5=
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17= 32.8+19= 5.2÷1.3= 1.6×0.4=
4.9×0.7= 1÷5= 6÷12= 0.87-0.49=
17×40= 100-63= 3.2+1.68= 2.8×0.4=
14-7.4= 1.92÷0.04= 0.32×500= 0.65+4.35=
10-5.4= 4÷20= 3.5×200= 1.5-0.06=
0.75÷15= 0.4×0.8= 4×0.25= 0.36+1.54=
1.01×99= 420÷35= 25×12= 135÷0.5=
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17= 32.8+19= 5.2÷1.3= 1.6×0.4=
4.9×0.7= 1÷5= 6÷12= 0.87-0.49=
17×40= 100-63= 3.2+1.68= 2.8×0.4=
14-7.4= 1.92÷0.04= 0.32×500= 0.65+4.35=
10-5.4= 4÷20= 3.5×200= 1.5-0.06=
0.75÷15= 0.4×0.8= 4×0.25= 0.36+1.54=
1.01×99= 420÷35= 25×12= 135÷0.5=
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17= 32.8+19= 5.2÷1.3= 1.6×0.4=
4.9×0.7= 1÷5= 6÷12= 0.87-0.49=
17×40= 100-63= 3.2+1.68= 2.8×0.4=
14-7.4= 1.92÷0.04= 0.32×500= 0.65+4.35=
10-5.4= 4÷20= 3.5×200= 1.5-0.06=
0.75÷15= 0.4×0.8= 4×0.25= 0.36+1.54=
1.01×99= 420÷35= 25×12= 135÷0.5=
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17= 32.8+19= 5.2÷1.3= 1.6×0.4=
4.9×0.7= 1÷5= 6÷12= 0.87-0.49=
17×40= 100-63= 3.2+1.68= 2.8×0.4=
14-7.4= 1.92÷0.04= 0.32×500= 0.65+4.35=
10-5.4= 4÷20= 3.5×200= 1.5-0.06=
0.75÷15= 0.4×0.8= 4×0.25= 0.36+1.54=
1.01×99= 420÷35= 25×12= 135÷0.5=
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17= 32.8+19= 5.2÷1.3= 1.6×0.4=
4.9×0.7= 1÷5= 6÷12= 0.87-0.49=
17×40= 100-63= 3.2+1.68= 2.8×0.4=
14-7.4= 1.92÷0.04= 0.32×500= 0.65+4.35=
10-5.4= 4÷20= 3.5×200= 1.5-0.06=
0.75÷15= 0.4×0.8= 4×0.25= 0.36+1.54=
1.01×99= 420÷35= 25×12= 135÷0.5=
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17= 32.8+19= 5.2÷1.3= 1.6×0.4=
4.9×0.7= 1÷5= 6÷12= 0.87-0.49=
17×40= 100-63= 3.2+1.68= 2.8×0.4=
14-7.4= 1.92÷0.04= 0.32×500= 0.65+4.35=
10-5.4= 4÷20= 3.5×200= 1.5-0.06=
0.75÷15= 0.4×0.8= 4×0.25= 0.36+1.54=
1.01×99= 420÷35= 25×12= 135÷0.5=
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17= 32.8+19= 5.2÷1.3= 1.6×0.4=
4.9×0.7= 1÷5= 6÷12= 0.87-0.49=
17×40= 100-63= 3.2+1.68= 2.8×0.4=
14-7.4= 1.92÷0.04= 0.32×500= 0.65+4.35=
10-5.4= 4÷20= 3.5×200= 1.5-0.06=
0.75÷15= 0.4×0.8= 4×0.25= 0.36+1.54=
1.01×99= 420÷35= 25×12= 135÷0.5=
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17= 32.8+19= 5.2÷1.3= 1.6×0.4=
4.9×0.7= 1÷5= 6÷12= 0.87-0.49=
17×40= 100-63= 3.2+1.68= 2.8×0.4=
14-7.4= 1.92÷0.04= 0.32×500= 0.65+4.35=
10-5.4= 4÷20= 3.5×200= 1.5-0.06=
0.75÷15= 0.4×0.8= 4×0.25= 0.36+1.54=
1.01×99= 420÷35= 25×12= 135÷0.5=
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17= 32.8+19= 5.2÷1.3= 1.6×0.4=
4.9×0.7= 1÷5= 6÷12= 0.87-0.49=
17×40= 100-63= 3.2+1.68= 2.8×0.4=
14-7.4= 1.92÷0.04= 0.32×500= 0.65+4.35=
10-5.4= 4÷20= 3.5×200= 1.5-0.06=
0.75÷15= 0.4×0.8= 4×0.25= 0.36+1.54=
1.01×99= 420÷35= 25×12= 135÷0.5=
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17= 32.8+19= 5.2÷1.3= 1.6×0.4=
4.9×0.7= 1÷5= 6÷12= 0.87-0.49=
17×40= 100-63= 3.2+1.68= 2.8×0.4=
14-7.4= 1.92÷0.04= 0.32×500= 0.65+4.35=
10-5.4= 4÷20= 3.5×200= 1.5-0.06=
0.75÷15= 0.4×0.8= 4×0.25= 0.36+1.54=
1.01×99= 420÷35= 25×12= 135÷0.5=
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17= 32.8+19= 5.2÷1.3= 1.6×0.4=
4.9×0.7= 1÷5= 6÷12= 0.87-0.49=
(4)396×[74-(4875÷15-13×21)]
(5)[1054-(174-168)]÷8
(6)6048÷[(107-99)×9]
Is that enough_ ∩)o



5/4*3/5=
5/4÷5/3=
0*5/11=
0÷3/2=
1/2*6=
6÷1/2=
1/10÷7/10=
28*7/4=
4/7÷4=
4/7÷8=
3÷1/10=
3/5÷1/5=
1/3÷4/3=
5/8*8/5=


5/4*3/5=0.75
5/4÷5/3=0.75
0*5/11=0
0÷3/2=0
1/2*6=3
6÷1/2=12
1/10÷7/10=1/7
28*7/4=49
4/7÷4=1/7
4/7÷8=1/14
3÷1/10=30
3/5÷1/5=3
1/3÷4/3=1/4
5/8*8/5=1



\(semicolon)
1\3*1\4=
4\25÷4\5=
1\4÷1\8=
1-1\5=
7\12+1\‘12=
5\12*6\5=
2\14*3=
2\5*1\4=
7\20÷4\15=
5*1\7=
5\6*3\5=
3\4+3\4=
2\3-1\6=
1÷3\4=
5\7÷5\2=


1\12
1\5
two
4\5
2\3
1\2
6\14
1\10
21\16
5\7
1\2
3\2
1\2
4\3
2\7



Sixth grade volume I oral arithmetic problem card answers of Hebei Education Press
Please, I can't stand it!


Nothing can be done



(1) The bottom area of the cylinder is 3.2 square decimeters and the side area is 6 square decimeters. The formula for calculating the surface area is ()
(2) The bottom radius of the cylinder is 4cm and the height is 10cm. The formula for calculating the surface area of the cylinder is ()
(3) The diameter of the bottom of the cylinder is 9 cm and the height is 12 cm. The formula for calculating the surface area of the cylinder is ()
(4) The circumference of the bottom surface of the cylinder is 12.56 cm and the height is 2 cm. The formula for calculating the surface area of the cylinder is ()
Do me a favor. Don't copy from others. I don't know if I say something. (the math teacher once said that we copied the key and difficult points) (*^__ ^*(hee hee, be precise.


1. Side area + 2 times surface area = 6 + 6.4 = 12.4
2. Bottom circumference × height = 2 × 4 × π × 10 = 80, π = 251.2
3. Bottom circumference × height = 9 × π × 12 = 108 π
four
12.56×2=25.12



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