Question

ap dung cac tinh chay phep cong va phep nhan de tinh nhanh

81 + 243 + 19

168+79+132

5.25.2.16.4

Answer 1

81 + 243 + 19 = (81 + 19) + 243 = 100 + 243 = 343

168 + 79 + 132 = (168 + 132) + 79 = 300 + 79 = 379

5.25.2.16.4 = (5.2).(25.4).16 = 10.100.16 = 16000

Answer 2

81 + 243 + 19=(81+19)+243=100+243=343

168+79+132=(168+132)+79=300+79=379

5.25.2.16.4=(5.2).(25.4).16=10.100.16=1000.16=16000

Answer 3

81 + 243 + 19

= ( 81 + 19 ) + 243 

=     100      +  243

=           343

168 + 79 + 132

= ( 168 + 132 ) + 79

=      300   +  79

=      379

5 . 25 . 2 . 16 . 4

= ( 5 . 2 ) . ( 25 . 4 ) . 16

=   10   . 100   . 16

=       1000      .       16

=            16 000

Answer 4

81+243+19

=81+19+243

=100+243

=343

168+79+132

=168+132+79

=300+79

=379

2.25.2.16.4

=(2.5).(25.4).16

=10.100.16

=16000