777*12+2*888巧算,67*21+18*21+85*79巧算

2025-04-13 12:34:40
推荐回答(1个)
回答1:

777*12+2*888
=111x7x12+2x8x111
=111x(84+16)
=111x100
=11100
67*21+18*21+85*79
=(67+18)x21+85x79
=85x21+85x79
=85x(21+79)
=85x100
=8500