Find 3 + 6 + 9 + 12 + +What is the sum of 93 + 96 + 99?

Find 3 + 6 + 9 + 12 + +What is the sum of 93 + 96 + 99?

3+6+9+12+…… +93+96+99
=（3+99）×33÷2
=102×33÷2
=1683

How about 3 + 6 + 9 + 12 + 15. + 96 + 99

3+6+9+12+15.+96+99=(3+99)*33/2=683
You can also do this: 3 + 6 + 9 + 12 + 15. + 96 + 99 = 3 * (1 + 2 + 3 +. + 33) = 3 * (1 + 33) * 33 / 2 = 1683

3 + 6 + 9 + 12.99 = (solved by Gauss algorithm)

=(3+99)+(6+96)+…… +(48+54)+51
=102+102+…… +102+51
=16×102+51
=1683

Simple calculation of 127.86 × 101-12.786 × 10

Original formula = 127.86x101-127.86
=127.86X(101-1)
=127.86X100
=12786

1 / (9 * 10) + 1 / (10 * 11) + 1 / (11 * 12) +. + 1 / (100 * 101)
How to calculate, must be simple, within 5 minutes

1 / (9 * 10) + 1 / (10 * 11) = 1 / 9-1 / 10 + 1 / 10-1 / 11, and so on ····································································

How can I calculate 0.35 * 101 * 3.5 easily? Am I right. (0.35 * 100 + 0.35 * 1) / 3.5 = 35.35 * 3.5 = 10.1
Sorry, the title is 0.35 * 101 / 3.5. Is my simple calculation right

It is estimated that the original problem is 0.35 × 101 ÷ 3.5. Your algorithm is not the most simple, but the simplest is as follows:
0.35×101÷3.5
=0.35÷3.5×101
=0.1×101
=10.1

The process of {3 / 10 minus 3 / 5} dividing by 7 / 10
The process of {3 / 4 minus 3 / 5} dividing by 7 / 10

Divide {3 / 4 minus 3 / 5} by 7 / 10
=Multiply {15 out of 20 minus 12 out of 20} by 10 out of 7
=3 out of 20 times 10 out of 7
=3 / 14

Simple calculation of 2 / 3 times 10 minus 2 / 3

2/3x10-2/3
=2/3x(10-1)
=2/3x9
=6

Simple operation: 11 / 15 times 9 / 10 plus 11 / 15 divided by 10?

11 out of 15 times 9 out of 10 plus 11 out of 15 divided by 10
=11/15*(9/10)+11/15*(1/10)
=11/15*(9/10+1/10)
=11/15*1
=11/15

How to calculate 8 out of 15 + 7 out of 15 △ 7 out of 10 + 1 out of 3? 9.6-11 △ 7 + 55 × 4?

8 / 15 + 7 / 15 △ 7 / 10 + 1 / 3
=8 out of 15 + 2 out of 3 + 1 out of 3
=8 / 15 + 1
=1 and 8 / 15
9.6-11÷7+55×4
=9.6-11/7+220
=228+7/4-11/7
=228 and 5 / 28