When Gauss was in elementary school, once after the teacher taught addition, he came up with a topic for students to calculate. The theme is:

1+2+3+ .....+97+98+99+ 100 = ?

The teacher is thinking, now the children must start class! I used this as an excuse to go out, but Gauss stopped me! ! It turns out that Gauss has worked it out. Little friend, do you know how he did it?

Gauss told everyone how he worked it out: add 1 to 100, and add 100 to 1, adding two lines, that is:

1+2+3+4+ .....+96+97+98+99+ 100

100+99+98+97+96+ .....+4+3+2+ 1

= 10 1+ 10 1+ 10 1+ .....+ 10 1+ 10 1+ 10 1+ 10 1

* * * There are one hundred sums 10 1, but the formula is repeated twice, so the answer is equal to < 5050 & gt.

Since then, the learning process of Gauss Elementary School has already surpassed other students, which laid the foundation for his future mathematics and made him a mathematical genius.

Length unit conversion 1 km = 1 000m 1 m =1decimeter1decimeter =10cm/kloc-0+00000 square meters/kloc-0. Gold RMB unit conversion 1 yuan = 10 angle 1 angle = 10 minute 1 yuan = 100 minute time unit conversion 1 century = 10 year = 65438+ February, 30 days of abortion: 4 \ 6 \ 9 \1,28 days in a normal year, 365 days in a normal year, 366 days in a leap year, 1 =24 hours, 1 =60 minutes.

formula

1, number of copies × number of copies = total number of copies/number of copies = total number of copies/number of copies = number of copies.

2. 1 multiple× multiple = multiple1multiple = multiple/multiple = 1 multiple

3. Speed × time = distance/speed = time/distance/time = speed

4. Unit price × quantity = total price ÷ unit price = total quantity ÷ quantity = unit price

5. Work efficiency × working hours = total workload ÷ work efficiency = working hours ÷ total workload ÷ working hours = work efficiency.

6. Appendix+Appendix = sum, and-one addend = another addend.

7. Minus-Minus = Minus-Minus = Minus+Minus = Minus

8. Factor × factor = product ÷ one factor = another factor.

9. Dividend = quotient dividend = divisor quotient × divisor = dividend

1. The construction site needs 106 tons of sand. First, automobile transportation 15 times, 2.4 tons each time. The rest are transported by cart, 5 tons each time. How many times will it take to complete?

1, ( 106-2.4× 15) ÷ 5 = 14

There used to be 30 boats in People's Park, which could bring 540 yuan's income every day. Now there are more 15 boats than before. What's your daily income now?

2, 540 ÷ 30× (30+15) = 810 (yuan

3. The TV factory originally planned to produce 1680 color TV sets in 36 days, and half of them were completed before 16 days. The rest of the plan will be completed within 6 days. How many units will be produced on average every day?

3 1680 ÷ 2 ÷ 6 = 140 (Taiwan Province)

There is a batch of coal in a factory, which was originally planned to burn 5 tons a day, which can burn for 45 days. In fact, it burns 0.5 tons less every day. How many days can this batch of coal burn?

4,5 x 45 ÷ (5-0.5) = 50 (days

5. To build the canal, it was originally planned to build 0.48km every day and complete it in 30 days. Actually, it's repairing 0.02 kilometers every day. How many days was it actually repaired?

5.0.48× 30 ÷ (0.48+0.02) = 28.8 (days)

6. Miss Wang reads a book. If he reads 32 pages every day, 15 days will be enough. Now you can read 40 pages a day, and you can finish it a few days in advance.

6. 15-32× 15 ÷ 40 = 3 (days)

7. A car traveled 260 kilometers in four hours. At this speed, it traveled for another 2.4 hours. How many kilometers have you traveled before and after? (Answer in two ways)