Tính nhanh: 1999-2000+2999-3000+3999-4000+4999-5000+5999-1000
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 nhanh
a) 1000-3999+400-4999+5000-5999+6000-6999-700
b) 3128-725-275
a, 1000-3999+400-4999+5000-5999+6000-6999-700
=(1000+5000+6000)+(-3999-4999-5999-6999)+(400-700)
=12000-13998-300
b,3128-725-275
=3128-(725-275)
=3128-450
=2678
tinh nhanh 1999-2000+2999-3000+399+400+4999-5000+5999=
1999 - 2000 + 2999 - 3000 + 399 + 400 + 4999 - 5000 + 5999= 2996
Tính nhanh :
1000 + 2000 + 3000 + 4000 + 5000 + 6000 + 7000 + 8000 + 9000 + 5000
1000 +9000 +2000+8000+3000+7000+4000+6000+5000+5000
= 10000+10000+10000+10000+10000
=50000
k nhá !
1000 + 1000 = ?
2000 + 2000 = ?
3000 + 3000 = ?
4000 + 4000 = ?
5000 + 5000 = ?
ARMY KẾT BN NHA
1000 + 1000 = 2000
2000 + 2000 = 4000
3000 + 3000 = 6000
4000 + 4000 = 8000
5000 + 5000 = 10000
kb nha
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
1000 + 2000 + 3000 + 4000 + 5000 =
15000 NHA BẠN AI K MÌNH MÌNH K LẠI CHO