666666*333333 Simple operation,

666666*333333 Simple operation,

666666*333333=222222*3*333333
=222222(1000000-1)
=222222000000-222222=222221777778

Fast simple algorithm 333333 × 777778 + 666666 × 111111

333333×777778＋666666×111111
＝333333×777778＋333333×2×111111
＝333333(777778＋222222)
＝333333×1000000

Calculate the following questions
21 and 7 / 8 - (1.875 + 1 and 7 / 10) 7 and 3 / 7 + (3 and 1 / 5-2 and 3 / 7) - 2 and 1 / 5
2 + 2 / 3 + 0.8 - (1.8-5 / 6) 1.625 + 4 + 6 / 7 + (4 + 3 / 8-3 + 6 / 7)
Another equation.
X - (2 1 / 20 + 5.75) = 8 / 15

1) The original formula = 175 / 8 - (15 / 8 + 17 / 10) + 16 / 5 - 17 / 7 - 11 / 5 = 175 / 8 - 15 / 8 - 17 / 10 + 16 / 5 - 17 / 7 - 11 / 5 = 175 / 8 - 15 / 8 + 16 / 5 - 11 / 5 - 17 / 10 - 17 / 7 = 20 + 1-17 / 10-17 / 7 = 193 / 10-17 / 7 = 1181 / 70

The following questions, how simple on how to calculate
8 / 15 - (2 / 15 + 2 / 5) 3 / 5 * 19 / 25 + 3 / 5 * 6 / 25 (7 / 10 + 2 / 5) * (3 / 2-2 / 3) 3 / 20 divided by [1 / 3 * (2 / 5 + 4 / 5)]

In the first question, the denominator of 2 / 5 is changed into 6 / 15, and the answer is 0
The second question put forward 3 / 5 (3 / 5) * (19 / 25 + 6 / 25) = 3 / 5
Question 3 (7 / 10 + 4 / 10) * (9 / 6-4 / 6) = 11 / 12
Question 4 (3 / 20) / (1 / 3 * 6 / 5) = (3 / 20) / (2 / 5) = 3 / 8