(1)5.24+7.9+4.76
=5.24+4.76+7.9
=10+7.9
=17.9;
(2)25×37×4
=25×4×37
=100×37
=3700;
(3)5.12-1.47-2.53
=5.12-(1.47+2.53)
=5.12-4
=1.12;
(4)56×125
=7×(8×125)
=7×1000
=7000;
(5)96.2+78-6.2
=96.2-6.2+78
=90+78
=168;
(6)450÷5÷9
=450÷(5×9)
=450÷45
=10;
(7)52×23+48×23
=(52+48)×23
=100×23
=2300;
(8)510-240÷12×15
=510-20×15
=510-300
=210;
(9)156×101-156
=156×(101-1)
=156×100
=15600;
(10)(2400-80×20)÷20
=(2400-1600)÷20
=800÷20
=40;
(11)4.5+3.15-4.5+3.15
=4.5-4.5+(3.15+3.15)
=0+6.3
=6.3.