First, calculate the following questions orally. (23 points)
10-2.65= 0.9×0.08= 528-349= 6+ 14.4= 24÷0.04=
12.34-2.3= 0÷3.8= 0.77+0.33= 7÷ 1.4= 67.5+0.25=7.2÷8×4= 5- 1.4- 1.6= 400÷ 125÷8= 1.9×4×0.5=
80×0. 125= 3× = 6 6= 2 -( + )= 10 2=
3.2×7÷3.2×7= ( - )× 12= 187.7× 1 1- 187.7= 1- 62.5%=
Two, write the laws or properties used in the simple operation of the following questions (12 points)
4 +3.2+5 +6.8 25×(8×0.4)× 1.25 7 -(2 - )
( ) ( ) ( )
( + + )×72 93.5÷3 16÷2.5
( ) ( ) ( )
Third, use a simple method to calculate. (65 points)
1 125-997 998+ 1246+9989 (8700+870+87)÷87
125×8.8 1.3+4.25+3.7+3.75 17. 15-(3.5-2.85)
3.4×99+3.4 4.8× 1.0 1 0.4×(2.5÷73)
( 1.6+ 1.6+ 1.6+ 1.6)×25 ( + - )÷
12.3-2.45-5.7-4.55 2 + 0. 125×0.25×64
64.2×87+0.642× 1300 78×36+7.8×74 1-7 17+ 8
0. 125× +0.5 2.42 +4.58 -43
25÷ 100 4.25-3 -(2 - 1 )
( 1) 1.25* 17.6+36. 1/0.8+2.36* 12.5
1.25* 17.6+36. 1/0.8+2.36* 12.5
=(5/4)* 17.6+36. 1*(5/4)+23.6*(50/4)
= 176/8+36 1/8+236/8
=773/8=96.625
(2)7.5*2.3+ 1.9*2.5
7.5*2.3+ 1.9*2.5
=7.5*( 1.9+0.4)+ 1.9*2.5
=(7.5+2.5)* 1.9+7.5*0.4
= 19+3 =22
(3)2004/2003*2005
2004/2003*2005
=(2004/2003)*(2003+2)
=2004+4008/2003
(4)276*543-267/276+543*275
276*543-267/276+543*275
=543*(276+275)-267/276
=543*55 1-267/276
1) 52 and 251× 79.45+159× 47.56+79 and 251× 52.44
=52.44×79.45+ 159×47.56+79.55×52.44
=52.44×(79.45+79.55)+ 159×47.56
=52.44× 159+ 159×47.56
= 159×(52.44+47.56)
= 159× 100
= 15900
3)2002+200 1-2000- 1999+ 1998+ 1997- 1996- 1995+……+2+ 1
=(2002-2000)+(200 1- 1999)+( 1998- 1996)+( 1997- 1995)+……+(6-4)+(5-3)+2+ 1
= 2+2+2+2+...+2+2 (from 3-2002 * * 2000, with 1000 binary) +2+ 1.
= 1000×2+2+ 1
=2003
Questions 4 and 5 both use a conversion formula1/(a× b) =1/(b-a )× (1/a-1/b).
Such as115 =1(3× 5) =1(5-3 )× (1/3-1/5) =/kloc-0.
4)( 1×2) +(2×3) +(3×4)+...+( 10× 1 1)
= 1/( 1×2)+ 1/(2×3)+ 1/(3×4)+……+ 1/( 10× 1 1)
=( 1- 1/2)+( 1/2 - 1/3)+( 1/3 - 1/4)+……+( 1/ 10 - 1/ 1 1)
= 1- 1/ 1 1
= 10/ 1 1
5) One third+one fifteenth+one thirty-fifth+one sixty-third+one ninety-ninth.
= 1/( 1×3)+ 1/(3×5)+ 1/(5×7)+ 1/(7×9)+ 1/(9× 1 1)
= 1/2×( 1- 1/3)+ 1/2×( 1/3- 1/5)+ 1/2×( 1/5- 1/7)+ 1/2×( 1/7- 1/9) + 1/2×( 1/9- 1/ 1 1)
= 1/2×( 1 - 1/3 + 1/3 - 1/5 + 1/5 - 1/7 + 1/7 - 1/9 + 1/9 - 1/ 1 1)
= 1/2×( 1- 1/ 1 1)
= 1/2× 10/ 1 1
=5/ 1 1
6) One sixth and seven fifths+twelve nineties and twenty+eleven thirty-thirteen forty-two+fifteen fifty-six.
(According to the prompt, 1 and 1/2= 1+ 1/2,+1/3 = 5/6 ...)
=( 1+ 1/2)-( 1/2+ 1/3)+( 1/3+ 1/4)-( 1/4+ 1/5)+( 1/5+ 1/6)-( 1/6+ 1/7)+( 1/7+ 1/8)
= 1+ 1/2 - 1/2 - 1/3 + 1/3 + 1/4 - 1/4 - 1/5 + 1/5 + 1/6 - 1/6 - 1/7 + 1/7 + 1/8
= 1+ 1/8
=9/8
Look carefully, it won't be difficult, everything can be calculated simply. See for yourself. Some local components will be easier to calculate. I'm not in grade five. I don't know if you study like us, but I can only find some. Sorry, please forgive me.
Simple calculation problems in the second volume of fifth grade mathematics 120 1. 5/2 -( 3/2+4/5)
2.7/8 + ( 1/8 + 1/9 )
3.5/6 + ( 1/2 + 2/3 )
4.9/7 - ( 2/7 - 10/2 1 )
5.3/7 + 49/9 + 4/7
6.8/9 + 15/36 + 3/27
7.5/2 - ( 3/2 + 4/5 )
8.7/8 + ( 1/8 + 1/9 )
9.9/7 - ( 2/7 - 10/2 1 )
10. 1/5 + ( 3/7 + 8/ 10 )
Simple operation:
1) 500+(407+0)
2) 386+382+ 1 14
3) 42+(9 1+ 158+ 109)
4) (87+ 103+ 1 13)+97
5) (246+387+ 154)+ 13
6) 49+(7 1+ 15 1+ 129)
7) 255+(79+45)
8) ( 169+39+ 13 1)+26 1
9) 2 19+ 175+ 18 1+225
10) 14+498+486
1 1)84× 10 1
12)(300+6)× 12
13)504×25
14)25×(4+8)
15)78× 102
16) 125×(35+8)
17)25×204
18)( 13+24)×8
19)99×64
20)99× 13+ 13
There must be an answer to the simple math problem 100 in the second volume of grade five. Where can I find the answer to the next simple math problem in the fifth grade? First, calculate the following questions orally
10-2.65= 0.9×0.08= 528-349= 6+ 14.4= 24÷0.04=
12.34-2.3= 0÷3.8= 0.77+0.33= 7÷ 1.4= 67.5+0.25=7.2÷8×4= 5- 1.4- 1.6=
00÷ 125÷8= 1.9×4×0.5=
80×0. 125= 3× = 6 6= 2 -( + )= 10 2=
3.2×7÷3.2×7= ( - )× 12= 187.7× 1 1- 187.7= 1- 62.5%=
Second, write down the laws or properties used in the simple operation of each of the following problems.
4 +3.2+5 +6.8 25×(8×0.4)× 1.25 7 -(2 - )
( ) ( ) ( )
( + + )×72 93.5÷3 16÷2.5
( ) ( ) ( )
720÷ 16÷5 630÷42 456-(256-36)
102×35 98×42 158+262+ 138 375+2 19+38 1+225
500 1-247- 102 1-232 ( 18 1+2564)+27 19 378+44+ 1 14+242+222
276+228+353+2 19 (375+ 1034)+(966+ 125) (2 130+783+270)+ 10 17
99+999+9999+99999 7755-(2 187+755) 22 14+638+286
3065-738- 1065 899+344 2357- 183-3 17-357
2365- 1086-2 14 497-299 2370+ 1995
Simple Math Questions and Answers Grade 5 (1)2.5*32*0. 125
=(2.5*4)*(8*0. 125)
= 10* 1
= 10
(2)3.5-7+6.5
=3.5+6.5-7
=3
(3) 1.2×2.5+0.8×2.5
=2.5( 1.2+0.8)
=25
(4)8.9× 1.25-0.9× 1.25
= 1.25(8.9-0.9)
= 10
(5) 12.5×7.4×0.8
= 12.5×0.8×7.4
=74
(6)6.5×9.5+6.5×0.5
=6.5×(9.5+0.5)
=6.5× 10
=65
(7)0.35× 1.6+0.35×3.4
=0.35*( 1.6+3.4)
=0.35*5
= 1.75
(8)6.72-3.28- 1.72
=6.75-(3.28+ 1.72)
=6.75-5
= 1.75
(9)0.45+6.37+4.55
=0.45+4.55+6.37
=5+6.37
= 1 1.37
( 10)28× 12.5- 12.5×20
=(28-20)* 12.5
=8* 12.5
= 100
( 1 1)23.65-(3.07+3.65)
=23.65-3.65-3.07
=20-3.07
= 16.93
( 12)(4+0.4×0.25)8×7× 1.25
=(4+ 1)*7* 10
=5*7* 10
=350
( 13) 1.65×99+ 1.65
= 1.65*(99+ 1)
= 1.65* 100
= 165
( 14)27.85-(7.85+3.4)
=27.85-7.85+3.4
=20+3.4
=23.4
( 15)48× 1.25+50× 1.25×0.2×8
7.8×9.9+0.78
=7.8*(9.9+0. 1)
=7.8* 10
=78
( 16)4.8×46+4.8×54
=(46+54)*4.8
= 100*4.8
=480
( 17)673-327- 173
=673-(327+ 173)
=673-500
= 173
( 18)4.44*2.5
= 1. 1 1*(4*2.5)
= 1. 1 1* 10
= 1 1. 1
( 19)3.5÷ 1.4
=(3.5÷0.7)÷( 1.4÷0.7)
=5÷2
=2.5
(20) 1+2+3+4+5......+99+ 100
=( 1+99)+(2+98)+(3+97)+......+(49+5 1)+50
=( 100÷2- 1)* 100+50
=4900+50
=4950
Is this ok?
Examples of simple calculation problems in the second volume of fifth grade mathematics 1, 5.76+13.67+4.24+6.33 = (5.76+4.24)+(13.67+6.33) =10+. 37.24+23.79-17.24 = 37.24-17.24+23.79 = 20+23.79 = 43.79 cases 3,4× 3.78× 0.25 = 4× 0.25× 3.78 = 125× 246× 0.8 =125× 0.8× 246 =100× 246 = 24,600 cases 5, (2.5+12.5 )× 40 = 2.5×. 3.68× 4.79+6.32× 4.79 = (3.68+6.32 )× 4.79 =10× 4.79 = 47.9 cases 7.26.86× 25.66-16.86× 25.66 = Kloc-0/01= 57× (100+1) = 57×100+57×1= 5757 cases1/kloc-0. = 7.8×1+7.8× 0.1= 7.8+0.78 = 8.58 cases 12, 25×32 =25×4×8 = 100×8 =800 cases. 125× 0.72 =125× 8× 0.09 =1000× 0.09 = 90 cases14,87× 2/85 = (85+2 )× 2/85. 56.5-3.7-6.3 = 56.5-(3.7+6.3) = 56.5-10 = 46.5 cases 16, 32.6 ÷ 0.4 ÷ 2.5 = 32.6 ÷ (0
The problems and answers of off-type calculation in the second volume of fifth grade mathematics are recursive equation calculation, which is an operation that completely writes out the calculation process, that is, the calculation that leaves the horizontal direction. When calculating mixed operations, it is usually to work out an expression step by step (step by step, you can't write an equal sign on the original formula), and the process of each step should be written out. Generally speaking, the equal sign should go forward and not be aligned with the first line. That is, to leave the original calculation. The main thing to master is to remember to calculate multiplication and division before adding and subtracting. In the successive calculation of multiplication and division, it should be calculated from left to right. When you encounter parentheses, you must first calculate the inside of parentheses. In the process of separation, the operation sequence line should be drawn according to the operation sequence, and the "three checks" should be done well. First of all, check whether the numbers and symbols copied from books to exercise books are correct. Second, check whether the numbers and symbols copied from horizontal to vertical are copied correctly. Third, it is necessary to check whether the draft is copied vertically, horizontally, and whether the decimal point position is correct or not.