45.6×9.9=45.6×(10-0.1)=45.6×10-4.56=456-4.56=4551.4445.6-0.99=45.6-1+0.01=44.6+0.01=44.6123.5×12.5×0.08=23.5×(12.5×0.08)=23.5×1=23.50.623×2.4+6.23×0.76=6.23×0.24+6.23×0.76=6.23×(0.24+0.76)=6.23×1=6.23