甲数是10.78,乙数比甲数多3.88,乙数是多少?
简算.×3+×5+×10 999×7+111×7(+++)×2002.
简算 ①9﹣(3+0.4) ②1.8×+2.2×25% ③×[0.75﹣(﹣)].
.
=
1990×2.8+199×51+1.99×2100.