a)300
b)374
c)4747
d)4530
e)2250
g)123123
Đây là toán lớp 4
a) 300
b) 374
c) 4747
d) 4530
e) 2250
g) 123123
a) 25 x 12 = 25 x 4 x 3 = 100 x 3 = 300
b) 34 x 11 = 34 x ( 10 + 1 ) = 34 x 10 + 34 x1 = 340 + 34 = 374
c) 47 x 101 = 47 x ( 100 + 1 ) = 47 x 100 + 47 x 1 = 4700 + 47 = 4747
d) 15 x 302 = 15 x ( 300 + 2 ) = 15 x 300 + 15 x 2 = 4500 + 30 = 4530
g) 123 x 1001 = 123 x ( 1000 + 1 ) = 123 x 1000 +123 x 1 = 123000 + 123 = 123123
tính nhanh:
a) 25 . 12
=5.5.12
=5. (5.12)
=5 . 60
=300
b) 34 . 11
=34 .(10+1)
=34.10 +34
=340+34
=374
c) 47 . 101
= 47.(100+1)
=47.100 +47
=4700 + 47
=4747
d) 15 . 302
= 5.3.151.2
= (151.3) .(5.2)
=453 . 10
=4530
e) 125. 18
= 125.6.3
=750.3
=2250
g) 123 .1001
=123.(1000+1)
=123.1000 + 123
=123000+123
=123123
a) 25 . 12
= 25 . 4 . 3
= 100 . 3 = 300
b) 34 . 11
= 34 . (10+1)
= 34 . 10 + 34 . 1
= 340 + 34 = 374
c) 47 . 101
= 47 . (100+1)
= 47 . 100 + 47.1
=4700 + 47 = 4747
d) 15 . 302
= (10+5) . 302
= 10 . 302 + 5.302
= 3020 + 1510 = 4530
e) 125 . 18
= 125 . (10+8)
= 125 . 10 + 125 . 8
= 1250 + 1000 = 2250
g) 123 . 1001
= 123 . (1000+1)
= 123.1000 + 123.1
= 123000 + 123 = 123123
25 x 12 = 300
34 x 11 = 374
47 x 101 = 4747
15 x 302 = 4530
125 x 18 = 2250
123 x 1001 = 123123
Học tốt!!!
a,25.12=(25.4).(12:4)=100.300
a,25.12=(25.4).(12:4)=100.3=300
b,34.11=34.(10+1)=34.10+34.1=340+34=374
c,47.101=47.(100+1)=47.100+47.1=4700+47=4747
d,15.302=15.(100+100+100+2)=15.100+15.100+15.100+15=1500+1500+1500+30=4530
e,125.18=125.(10=8)=125.10+125.8=1250+1000+2250
g,123.1001=123.(1000+1)=123.1000+123.1=123000+123=123123
