A simple calculation method of 999 × 21 + 666 × 45-333 × 53 Urgent! Homework tonight!

A simple calculation method of 999 × 21 + 666 × 45-333 × 53 Urgent! Homework tonight!

999×21+666×45-333×53
=333×63+333×90-333×53
=333×(63+90-53)
=333×100
=33300

999×888+888×777+777×666=?

999×888+888×777+777×666
=111×9×111×8+111×8×111×7+111×7×111×6
=111×111×（9×8+8×7+7×6）
=111×111×170
=2094570

How to calculate 999.999 △ 666.666?

999.999÷666.666
=111·111×9÷(111·111×6)
=111·111÷111·111×(9÷6)
=9／6
=3／2

333 × 17 + 999 × 27 + 666

333×17+999×27+666
=333×17+333×3×27+333×2
=333×（17+3×27+2）
=333×（17+81+2）
=333×100
=33300
Happy study