(1)(136-87)×15÷3
=49×15÷3
=735÷3
=245;
(2)542×6+158×6
=(542+158)×6
=700×6
=4200;
(3)98×101
=98×100+98×1
=9800+98
=9898;
(4)168+32÷8
=168+4
=172;
(5)101×42-42
=(101-1)×42
=100×42
=4200;
(6)4.9+0.1-4.9+0.1
=4.9-4.9+(0.1+0.1)
=0+0.2
=0.2;
(7)34.02+13.5+0.98
=34.02+0.98+13.5
=35+13.5
=48.5;
(8)5.17-1.8-3.2
=5.17-(1.8+3.2)
=5.17-5
=0.17;
(9)9.95-(4.95+3.14)
=9.95-4.95-3.14
=5-3.14
=1.86;
(10)8.43+2.87+0.57+0.13
=8.43+0.57+(0.13+2.87)
=9+3
=12.