Học toán nàooooo!!(nâng cao)
Bài 1.1: Tính nhanh:
237 + 357 + 763
2345 + 4257 - 345
5238 - 476 + 3476
1987 - 538 - 462
4276 + 2357 + 5724 + 7643
3145 + 2496 + 5347 + 7504 + 4653
2376 + 3425 - 376 - 425
3145 - 246 + 2347 - 145 + 4246 - 347
4638 - 2437 + 5362 - 7563
3576 - 4037 - 5963 + 6424
Bài 1.2: Tính nhanh:
5+ 5 + 5 + 5+ 5 + 5 +5+ 5 + 5 +5
25 + 25 + 25 + 25 + 25 + 25 +25 + 25
45 + 45 + 45 + 45 + 15 + 15 + 15 + 15
2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 + 18
125 + 125 + 125 + 125 - 25 - 25 - 25 - 25
bruh bấm máy tính.
Bài 1.1:
237 +357 +763 = 1357
2345 + 4257 - 345 = 6257
5238 - 476 + 3476 = 8238
1987 - 538 - 462 = 987
4276 + 2357 + 5724 + 7643 = 20000
3145 + 2496 + 5347 + 7504 + 4653 = 23145
2376 + 3425 - 376 - 425 = 500
3145 - 246 + 2347 - 145 + 4246 - 374 = 9000
4638 - 2437 + 5362 - 7563 = 0
3576 - 4037 - 5963 + 6424 = 0
Bài 1.2:
5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 = 5 x 10 = 50
25 + 25 + 25 + 25 + 25 + 25 + 25 + 25 = 25 x 8 = 200
45 + 45 + 45 + 45 + 15 + 15 + 15 + 15 = 45 x 4 + 15 x 4 =180 + 60 = 240
2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 + 18 = (2 + 18) + (4 + 16) + (6 + 14) + (8 + 12) +10 = 20 + 20 + 20 + 20 + 10 = 90
125 + 125 + 125 + 125 - 25 - 25 - 25 - 25 = 125 x 4 - 25 x 4 = 500 - 100 = 400
Chúcc bạnn họcc tốtt.
Tính hợp lý:
a) 815 - 23 - 77 + 185
b) 3145 - 246 + 2347 - 145 + 4246 - 347
c) 2018 : 1 - 2018 . 1 : 2018 . 2008 + 2018 . 2002
d) 9 - 8 - 7 - . . . - 2 - 1 . ( 500 . 9 - 250 . 18 )
Tính hợp lý:
a, 815 – 23 – 77 + 185
b, 3145 – 246 +2347 – 145 + 4246 – 347
c, (2018:1 – 2018.1):(2018.2008 + 2018.2002)
d, (9 – 8 – 7 – … – 2 – 1).(500.9 – 250.18)
a) 815 – 23 – 77 +185 = (815 + 185) – (23+77) = 1000 – 100 = 900
b) 3145 – 246 + 2347 – 145 + 4246 – 347
= (3145-145) + (4246 – 246) + (2347 – 347)
= 3000 + 4000 + 2000 = 9000
c) (2018:1 – 2018.1):(2018.2008+2018.2002) = 0 : (2018.2008+2018.2002) = 0
d) (9 – 8 – 7 – 6 – … – 2 – 1).(500.9 – 250.18)
= (9 – 8 – 7 – 6 – … – 2 – 1).(500.9 – 250.2.9)
= (9 – 8 – 7 – 6 – … – 2 – 1).(500.9 – 500.9)
= (9 – 8 – 7 – 6 – … – 2 – 1).0 = 0
1 : Tính nhanh:
a, 2376 + 3425 - 376 - 425
b, 4638 - 2437 + 5362 - 7563
c, 45 + 45 + 45 + 45 + 15 + 15 + 15 + 15
d, 4 x 125 x 25 x 8
e, 2 x 8 x 50 x 25 x 125
2 : Tính nhanh bằng hai cách:
125 + 125 + 125 + 125 - 25 - 25 - 25 - 25
1 : Tính nhanh:
a) 2376 + 3425 - 376 - 425 = ( 2376 - 376 ) + ( 3425 - 425 )
= 2000 + 3000
= 5000
b)4638 - 2437 + 5362 - 7563 = 2210 + ( - 2210 )
= 0
c) 45 + 45 + 45 + 45 + 15 + 15 + 15 + 15
= 45 x 4 + 15 x 4
= ( 45 + 15 ) x 4
= 60 x 4
= 240
d) 4 x 125 x 25 x 8 = ( 4 x 25 ) x ( 125 x 8 )
= 100 x 1000
= 100000
e) 2 x 8 x 50 x 25 x 125 = ( 2 x 50 ) x ( 8 x 125 ) x 25
= 100 x 1000 x 25
= 100000 x 25
= 2500000
2 : Tính nhanh bằng 2 cách:
C1 : 125 + 125 + 125 + 125 - 25 - 25 - 25 - 25
= ( 125 - 25 ) + ( 125 - 25) + ( 125 - 25 ) + ( 125 - 25 )
=100 + 100 + 100 + 100
= 100 x 4
= 400
C2 : 125 + 125 + 125 + 125 - 25 - 25 - 25 - 25
= 125 x 4 - 25 x 4
= ( 125 - 25 ) x 4
= 100 x 4
= 400
1: Tính nhanh:
a, 2376 + 3425 - 376 - 425
= ( 2376 - 376 ) + ( 3425 - 425 )
= 2000 + 3000
= 5000.
b, 4638 - 2437 + 5362 - 7563
= 2210 + (-2210)
= 0.
c, 45 + 45 + 45 + 45 + 15 + 15 + 15 + 15 + 15
= ( 45 + 15 ) + ( 45 + 15 ) + ( 45 + 15 ) + ( 45 + 15 )
= 60 + 60 + 60 + 60
= 240.
d, 4 x 125 x 25 x 8
= ( 4 x 25 ) x ( 125 x 8 )
= 100 x 1000
= 100000.
e, 2 x 8 x 50 x 25 x 125
= ( 2 x 50 ) x ( 8 x 125 ) x 25
= 100 x 1000 x 25
= 2500000.
2: Tính nhanh bằng hai cách:
125 + 125 + 125 + 125 - 25 - 25 - 25- 25
= ( 125 - 25 ) + ( 125 - 25 ) + ( 125 - 25 ) + ( 125 -25 )
= 100 + 100 + 100 + 100
= 400.
tính nhanh
3145 - 246 + 2347 - 145 + 4246 - 347
81,3x99 + 82 -0,7
124 x 76 +12 x 248
128 x 68 + 16 x 256
17,8 x 99 +17 + 0,8
3145-246+2347-145+4246-347
=(3145-145)+(2347-347)+(4246-246)
=3000+2000+4000=9000
minh chi lam dk câu ý thui
câu 4:tính bằng cách thuận tiện
a.4276+2357+5724+7643
b.3145-246+2347-145+4246-347
c.(45-5x9)x2x3x4x5x6x7x8x9
a.(4276+5724)+(2357+7643)
=10000 + 10000
=20000
b.câu này không biết:)))
c.câu này cũng không biết :)))
a)4276+2357+5724+7643
= (4276+5724)+(2357+7643)
= 1000+1000
= 2000
b)3145-246+2347-145+4246-347
= (3145-145)+(4246-246)+(2347-347)
= 3000+4000+2000
= 9000
c)(45-5x9)x2x3x4x5x6x7x8x9
= (45-45)x2x3x4x5x6x7x8x9
=0x2x3x4x5x6x7x8x9
=0
c.(45-5x9)x2x3x4x5x6x7x8x9
=(45-45)x2x3x4x5x6x7x8x9
=0x2x3x4x5x6x7x8x9
=0
thui nha=)))
Tính nhanh:
3145 - 246 + 2347 - 145 + 4246 - 347
3145 - 246 + 2347 - 145 + 4246 - 347
= (3145 - 145) + (4246 - 246) + (2347 - 347)
= 3000 + 4000 + 2000
= 7000 + 2000
= 9000
3145 - 246 + 2347 - 145 + 4246 - 347
= (3145 - 145) + (2347 - 347) + (4246 - 246)
= 3000 + 2000 + 4000
= 5000 + 4000
= 9000
Tk cho mình nha ae!!!!!!!!!!!!!!! Ai tk mình thì mình tk lại.
Tính nhanh :
3145 - 246 + 2347 - 145 + 4246 - 347
= ( 3145 - 145 ) + ( 2347 - 347 ) + ( 4246 - 246 )
= 3000 + 2000 + 4000
= 5000 + 4000
= 9000
tính nhanh
349 + 602 + 651 + 398
3145 - 246 + 2347 - 145 + 4246 - 347
a)
349 + 602 + 651 + 398
= (349 + 651 ) + (602 + 398)
= 1000 + 1000
= 2000
b)
3145 - 246 + 2347 - 145 + 4246 - 347
= (3145 - 145) + (4246 - 246) + (2347 - 347)
= 3000 + 4000 + 2000
= 7000 + 2000
= 9000
\(349+602+651+398\)
\(=\left(349+651\right)+\left(602+398\right)\)
\(=1000+1000\)
\(=2000\)
_____
\(3145-246+2347-145+4246-347\)
\(=\left(3145-145\right)+\left(2347-247\right)+\left(4246-246\right)\)
\(=3000+2000+4000\)
\(=9000\)
\(349+602+651+398=\left(349+651\right)+\left(602+398\right)=1000+1000=2000\)\(3145-246+2347-145+4246-347=\left(3145-145\right)+\left(4246-246\right)+\left(2347-347\right)=3000+4000+2000=9000\)
a. (72 - 8 x9 ) : ( 20 + 21 + 22 + 23 + 24 + 25)
b. (500 x 9 - 250 x18 ) x (1 + 2 + 3 + ...+9)
c. (11 + 13 + 15 + ...+ 19) x (6 x 8 - 48)
a) ( 72 - 8x9 ) : ( 20 + 21 + 22 + 23 + 24 + 25 )
= ( 72 - 72 ) : ( 20 + 21 + 22 + 23 + 24 + 25 )
= 0 : ( 20 + 21 + 22 + 23 + 24 + 25 )
= 0
b) ( 500 x 9 - 250 x 18 ) x ( 1 + 2 + 3 + ... + 9 )
= ( 250 x 2 x 9 - 250 x 18 ) x ( 1 + 2 + 3 + ... + 9 )
= ( 250 x 18 - 250 x 18 ) x ( 1 + 2 + 3 + ... + 9 )
= 0 x ( 1 + 2 + 3 + ... + 9 )
= 0
c ) ( 11 + 13 + 15 + ... + 19 ) x ( 6 x 8 - 48 )
= ( 11 + 13 + 15 + ... + 19 ) x ( 48 - 48 )
= ( 11 + 13 + 15 + ... + 19 ) x 0
= 0
a) ( 72 - 8x9 ) : ( 20 + 21 + 22 + 23 + 24 + 25 )
= ( 72 - 72 ) : ( 20 + 21 + 22 + 23 + 24 + 25 )
= 0 : ( 20 + 21 + 22 + 23 + 24 + 25 )
= 0
b) ( 500 x 9 - 250 x 18 ) x ( 1 + 2 + 3 + ... + 9 )
= ( 250 x 2 x 9 - 250 x 18 ) x ( 1 + 2 + 3 + ... + 9 )
= ( 250 x 18 - 250 x 18 ) x ( 1 + 2 + 3 + ... + 9 )
= 0 x ( 1 + 2 + 3 + ... + 9 )
= 0