Tính nhanh:
a) 38,42 + 19,5 + 61,58 + 80,5
= ...............…………………………
= ...............…………………………
b) 50 x 7,82 x 2
= ...............…………………………
= ...............…………………………
c) 125,7 x 22 + 125,7 x 78
= ...............…………………………
= ...............…………………………
d) 3,4 x 1,1 + 6,6 x 1,1
= ...............…………………………
= ...............…………………………
a ) 38,42 + 19,5 + 61,58 + 80,5
= ( 38,42 + 61,58 ) + ( 19,5 + 80,5 )
= 100 + 100
= 200
b) 50 x 7,82 x 2
= ( 50 x 2 ) x 7,82
= 100 x 7,82
= 782
c) 125,7 x 22 + 125,7 x 78
= 125,7 x ( 22 + 78 )
= 125,7 x 100
= 12570
d) 3,4 x 11 + 6,6 x 11
= ( 3,4 + 6,6 ) x 11
= 10 x 11
= 110
Tính nhanh:
a) 38,42 + 19,5 + 61,58 + 80,5
= .( 38,42 + 61,58 ) + ( 19,5 + 80,5 )
= 100 + 100..............………………
= ......200.........……………………...
b) 50 x 7,82 x 2
= .50 x 2 x 7,82...........
= 100 x 7,82..............
= .......782........………
c) 125,7 x 22 + 125,7 x 78
= ..125,7 x ( 22 + 78 )
= 125,7 x 100.............…………………………
= .........12570......…………………………
d) 3,4 x 1,1 + 6,6 x 1,1
= ....( 3,4 + 6,6 ) x 1,1
= 10 x 1,1...........…………………………
= .......11........…………………………
\(a,38,42+19,5+61,58+80,5\)
\(=\left(38,42+61,58\right)+\left(19,5+80,5\right)\)
\(=100+100\)
\(=200\)
\(b,50\times7,82\times2\)
\(=\left(50\times2\right)\times7,82\)
\(=100\times7,82\)
\(=782\)
\(c,125,7\times22+125,7\times78\)
\(=125,7\times\left(22+78\right)\)
\(=125,7\times100\)
\(=12570\)
\(d,3,4\times1,1+6,6\times1,1\)
\(=1,1\times\left(3,4+6,6\right)\)
\(=1,1\times10\)
\(=11\)
a) 38,42 + 19.5 + 61,58 + 80,5
= (38,42 + 61,58) + ( 19,5 + 80,5 )
= 100 + 100 = 200
b) 50 x 7,82 x 2
= 50 x 2 x 7,82
= 100 x 7,82 = 782
c) 125,7 x 22 + 125,7 x 78 d) 3,4 x 1,1 + 6,6 x 1,1
= 125,7 x ( 22 +78 ) = (3,4 + 6,6 ) x 1,1
= 125,7 x 100 = 10 x 1,1
= 12570 = 11