Tính nhanh
a) 1000-3999+400-4999+5000-5999+6000-6999-700
b) 3128-725-275
Tính nhanh: 1999-2000+2999-3000+3999-4000+4999-5000+5999-1000
1999-2000+2999-3000+3999-4000+4999-5000+5999-1000
=(1999-2000)+(2999-3000)+(3999-4000)+(4999-5000)+(5999-1000)
=-1+(-1)+(-1)+(-1)+4999
=-1x4+4999
=-4+4999
=4999-4
=4995
1999 - 2000 + 2999 - 3000 + 3999-4000+ 4999-5000+5999-1000
= ( 2000-1999) + ( 3000-2999) + ( 4000-3999) + ( 5999-5000) -1000
= 1 + 1 + 1 + 1 -1000
=4 -1000
= 1000-4
=996
1999-2000+2999-3000+3999-4000+4999-5000+5999-1000=4995
k cho mk nha năn nỉ đó
tinh nhanh (tong day so ) :
1999 - 2000 + 2999 - 3000 + 3999 - 4000 + 4999 - 5000 + 5999 - 1000
1999 - 2000 + 2999 - 3000 + 3999 - 4000 + 4999 - 5000 + 5999 - 1000
=(1999-2000)+(2999-3000)+(3999-4000)+(4999-5000)+(5999-1000)
=1+(-1)+(-1)+(-1)+4999
=1x4+4999
=4+4999
=4999-4
=4995
tk nha
cac ban chinh bay cach giai ra nhe . day la tinh nhanh ma .
5999 – 2000 + 4999 – 3000 + 3999 – 4000 + 2999 – 5000 + 1999 – 100
Trình bày lời giải nhé
5999 - 5000 + 4999 - 4000 + 3999 - 3000 + 2999 - 2000 + 1999 - 100
= 999 + 999 + 999 + 999 + 1899
= 999 x 4 + 1899
= 5895
tính nhanh:
2-4+6-8+10-12+14-16+18-20+22
10+12+14+16+...+80
1999-2000+2999-3000+3999-4000+4999-5000+5999-1000
60-61+50-51+40-41+30-31+20-21+10-11+70
2-4+6-8+10-12+14-16+18-20+22
=(2+18)-(4+16)+(6+14)-(8+12)-(10+20)+22
=20-20+20-20-20+22
=22-20
=2
1999-2000+2999-3000+3999-4000+4999-5000+5999-1000
=(1999-1000)+(2999-2000)+(3999-3000)+(4999-4000)+(5999-5000)
=999x5
=4995
2-4+6-8+10-12+14-16+18-20+22 =2+(6-4)+(10-8)+(14-12)+(18-16)+(22-20) = 2+2+2+2+2+2 = 12
Tính nhẩm:
a) 3000 + 5000 = ..........
5000 + 5000 = ..........
4000 + 4000 = ..........
7000 + 2000 = ..........
6000 + 1000 = ..........
2000 + 8000 = ..........
b) 2000 + 700 = ..........
100 + 1000 = ..........
6000 + 600 = ..........
8000 + 500 = ..........
5000 + 300 = ..........
400 + 6000 = ..........
a) 3000 + 5000 = 8000
5000 + 5000 = 10 000
4000 + 4000 = 8000
7000 + 2000 = 9000
6000 + 1000 = 7000
2000 + 8000 = 10 000
b) 2000 + 700 = 2700
100 + 1000 = 1100
6000 + 600 = 6600
8000 + 500 = 8500
5000 + 300 = 5300
400 + 6000 = 6400
a) 3000+5000=8000
5000+5000=10000
4000+4000=8000
7000+2000=9000
6000+1000=7000
2000+8000=10000
b) 2000+700=2700
100+1000=1100
6000+600=6600
8000+500=8500
5000+300=5300
400+6000=6400
a) 3000 + 5000 = 8000
5000 + 5000 = 10000
4000 + 4000 =8000
7000 + 2000 = 9000
6000 + 1000 = 7000
2000 + 8000 = 10000
b) 2000 + 700 = 9000
100 + 1000 = 1100
6000 + 600 =12000
8000 + 500 = 13000
5000 + 300 = 5300
400 + 6000 = 6400
Tính nhẩm:
5000 + 100 = ..................
7400 - 400 = ..................
2000 3 + 600 = ..................
8000 : 2 + 2000 = ..................
6000 - (5000 - 1000) = ..................
6000 - 5000 + 1000 = ..................
7000 - 3000 x 2 = ..................
(7000 - 3000) x 2 = ..................
5000 + 100 = 5100
7400 - 400 = 7000
2000 3 + 600 = 6600
8000 : 2 + 2000 = 6000
6000 - (5000 - 1000) = 2000
6000 - 5000 + 1000 = 2000
7000 - 3000 x 2 = 1000
(7000 - 3000) x 2 = 8000
5000 + 100 = 5100
7400 - 400 = 7000
2000 3 + 600 = 6600
8000 : 2 + 2000 = 6000
6000 - (5000 - 1000) = 2000
6000 - 5000 + 1000 = 2000
7000 - 3000 x 2 = 1000
(7000 - 3000) x 2 = 8000
5000 + 100 = 5100
7400 - 400 = 7000
2000 3 + 600 = 6600
8000 : 2 + 2000 = 6000
6000 - (5000 - 1000) = 2000
6000 - 5000 + 1000 = 2000
7000 - 3000 x 2 = 1000
(7000 - 3000) x 2 = 8000
Điền (< ; > ; =).
2478 ... 4132 6000 ... 5999 9000 ... 7989
5578 ... 5576 7100 ... 7010 6840 + 7 ... 6847
9900 + 99 ... 10 000 5000 + 5 ... 5005 7890 ... 7989
2478 < 4132 6000 > 5999 9000 > 7989
5578 > 5576 7100 < 7010 6840 + 7 = 6847
9900 + 99 < 10 000 5000 + 5 = 5005 7890 < 7989.
tinh nhanh 1999-2000+2999-3000+399+400+4999-5000+5999=
1999 - 2000 + 2999 - 3000 + 399 + 400 + 4999 - 5000 + 5999= 2996
a) 9000 - 7000 = ...............
3000 - 2000 = ...............
8000 -8000 = ...............
5000 - 1000 = ...............
6000 - 5000 = ...............
10000 - 2000 = ...............
b) 4600 - 400 = ...............
8500 - 500 = ...............
9900 - 300 = ...............
6800 - 700 = ...............
7200 - 3000 = ...............
5600 - 2000 = ...............
3800 - 3000 = ...............
7400 - 400 = ...............
a) 9000 - 7000 = 2000
3000 - 2000 = 1000
8000 -8000 = 0
5000 - 1000 = 4000
6000 - 5000 = 1000
10000 - 2000 = 8000
b) 4600 - 400 = 4200
8500 - 500 = 8000
9900 - 300 = 9600
6800 - 700 = 6100
7200 - 3000 = 4200
5600 - 2000 = 3600
3800 - 3000 = 800
7400 - 400 = 7000
a)9000-7000=2000
3000-2000=1000
8000-8000=0
5000-1000=4000
6000-5000=1000
10000-2000=8000
b)4600-400=4200
8500-500=8000
9900-300=9600
6800-700=6100
7200-3000=4200
5600-2000=3600
3800-3000=800
7400-400=7000
a) 9000 - 7000 = 2000
3000 - 2000 = 1000
8000 -8000 = 0
5000 - 1000 = 4000
6000 - 5000 = 1000
10000 - 2000 = 8000
b) 4600 - 400 = 4200
8500 - 500 = 8000
9900 - 300 = 9600
6800 - 700 = 6100
7200 - 3000 = 4200
5600 - 2000 = 3600
3800 - 3000 = 800
7400 - 400 = 7000