（1）624-3.2×1.5÷0.1=624-4.8÷0.1=624-48=576；（2）9.43+0.78-2.43=9.43-2.43+0.78=7+0.78=7.78；（3）5.7×2.8+5.7×6.2+5.7=5.7×（2.8+6.2+1）=5.7×10=57；（4）7.6×5+2.4÷ 1 5 =7.6×5+2.4×5=（7.6+2.4）×5=10×5=50．
