数学简算题,好像有点难...也好像不难...⑴9999×7778+3333×6666⑵5.6×69.32＋138.64×0.05＋693.2×0.43

Question

数学简算题,好像有点难...也好像不难...
⑴ 9999×7778+3333×6666
⑵ 5.6×69.32＋138.64×0.05＋693.2×0.43

Answer 1

9999×7778+3333×6666
原式=9999×7778+3333×3×2222
=9999×7778+9999×2222
=9999×（7778+2222）
=9999×10000
=99990000
5.6×69.32＋138.64×0.05＋693.2×0.43
=5.6×69.32＋69.32×2×0.05＋69.32×4.3
=5.6×69.32＋69.32×0.1＋69.32×4.3
=(5.6＋0.1＋4.3)×69.32
=10×69.32
=693.2