(1)54.8+23+15.2+77
=(54.8+15.2)+(23+77)
=70+100
=170;
(2)43.5-6.5-13.5
=43.5-(6.5+13.5)
=43.5-20
=23.5;
(3)(300+750÷15)×8
=(300+50)×8
=350×8
=2800;
(4)84×15+116×15
=(84+116)×15
=200×15
=3000;
(5)125×24
=125×(8×3)
=(125×8)×3
=1000×3
=3000;
(6)184+240÷8×16
=184+30×16
=184+480
=664;
(7)(25+45)×4
=25×4+45×4
=100+180
=280;
(8)1240÷25÷4
=1240÷(25×4)
=1240÷100
=12.4;
(9)202×48
=(200+2)×48
=200×48+2×48
=9600+96
=9696.