1.10x9+20x9+100x9 2.14x14+14x29+14x147+14x10 000 3.365+365+265+265+165+165+65+65
Bài 41:Nhân, chia với10,100,1 000,...
1,tính nhẩm
14x10 1348x100 5629x1000
18390/10 328000/100 378000/1000
1. TÍNH NHẨM
14x10=140
1348x100=134800
5629x1000=5629000
18390 : 10=1839
328000 : 100=3280
378000 : 1000=378
14 x 10 = 140
1348 x 100 = 134800
5629 x 1000 = 5629000
18390 : 10 = 1839
328000 : 100 = 3280
378000 : 1000 = 378
Cho 1 like
3x9+10-20x9 = ?
14x29+14x71+(1+2+3+....+999)(199199x198-198198x199) = ?
14.29+14.71+(1+2+3+...+2015)(199199.198-198198.199)
=14(29+71)+(1+2+3+...+2015)(199.1001.198-198.1001.199)
=14.100+(1+2+3+...+2015)0=1400+0=1400
14.(29+71)+(1+2+3+...999).0
14.100+(1+2+3...999).0
14000+(1+2+3+...999).0
Chú ý : số 0 luôn nhân với bao nhiêu thì vẫn bằng 0
Nên tổng trên bằng 0
tính nhanh: 20x10+20x9+20x11+10x2+10x3+10x4+10x1
=> 20 x ( 10 + 9 + 11 ) + 10 x ( 2 + 3 + 4 + 1 )
=> 20 x 30 + 10 x 10
=> 600 + 100
=> 700
20x10+20x9+20x11+10x2+10x3+10x4+10x1
=20x(10+9+11)+10x(2+3+4+1)
=20x30+10x10
=600+100
=700
20x9+20x90+20
K mik rùi mik k lại nhé
\(20\cdot9+20\cdot90+20\)
\(=20\cdot\left(90+9+1\right)\)
\(=20\cdot100\)
\(=2000\)
20x9+20x90+20
=20x(9+90+1)
=20x100
=2000
K mik rùi mik k lại
20x9+20x90+20= 2000
k mik nha mik thề sẽ k cho các bn
100x9 + 100x10 + 2000
100x9 + 100x10 + 2000
= 900+ 1000 +2000
= 1900 +2000
= 3900
100x9+100x10+2000
=100x9+100x10+100x20
=100x(9+10+20)
=100x39
=3900
100x9 + 100x10 +2000 = 900 + 1000 +2000 =3900
100x10+100x9+100
100 x 10 + 100 x 9 + 100
= 100 x 10 + 100 x 9 + 100 x 1
= 100 x (10 + 9 + 1)
= 100 x 20
= 2000
100x9+100x10=?
kb với mình nha
tính nhanh
100+100x9+100x2-100
100+100x9+100x2-100
= 100*1+100x9+100x2-100*1
= 100 * (1+9+2-1)
= 100* 11
= 1100