Last year, Xingfu road primary school donated 6320 yuan to the Wenchuan earthquake stricken area. The sixth grade students donated 32 yuan as much as the fifth grade students. How much did the fifth grade students donate?

Last year, Xingfu road primary school donated 6320 yuan to the Wenchuan earthquake stricken area. The sixth grade students donated 32 yuan as much as the fifth grade students. How much did the fifth grade students donate?

6320 (1 + 32) = 6320 (52) = 2528 (yuan) a: the fifth grade students donate 2528 yuan

In the donation activities for the Wenchuan earthquake disaster area in 200, Xiangyang primary school donated 40000 yuan, and Lantian primary school donated 1500 yuan more than Xiangyang primary school
How many ten thousand yuan do you donate?

4 / 5 + 0.15 = 0.95 (ten thousand yuan)
4 / 5 + 0.95 = 17500 yuan

If the unit price of a commodity is 180 yuan after 10% price reduction, its unit price before price reduction is 180 yuan______ Yuan

According to the equation: X-10% x = 180, the solution is x = 200

If f (x + y) = f (x) + F (y), f (8) = 3, then f (2)=______ ．

∵ f (x + y) = f (x) + F (y), f (8) = 3, ∵ let x = y = 4, then f (8) = 2F (4) = 3, ∵ f (4) = 32, let x = y = 2, f (4) = 2F (2) = 32, ∵ f (2) = 34

Find out ten approximate numbers from the newspaper

Example:
(1) The output value of a factory in 1998 was about 15 million yuan, about 12 times that of 1978;
(2) There are 52 students in class 2 of grade 1 of junior high school. The average height is about 1.57 meters and the average weight is about 50.5 kg;
(3) By calculation, the circumference of a circle with a diameter of 10 cm is 31.4 cm;
(4) In 1999, China's national economy grew by 7.8%
Exact number:
(1) 1998 and 1978 (years are exact)
(2) 52 (52 is prime)
(3) 10 (10 cm is a precise distance)
(4) 1999 (year is exact)
Approximate number:
(1) 15 million and 12 (approximate 15 million yuan, accurate to 10000 bits, with four significant digits; approximate 12, accurate to 10000 bits, with two significant digits)
(2) 1.57 and 50.5 (approximate 1.57 to percentile, 3 significant digits; approximate 50.5 to decile, 3 significant digits)
(3) 31.4 (because 3.14 is an approximation of π and PI is divisible, 31.4 is an approximation)
(4) 7.8% (when it is not easy to get or can not get the correct number, only the approximate number can be obtained. For example, the result of the census can only be an approximate number.)
Do you understand

The price of a commodity is increased by 1 / 10 and then decreased by 1 / 10. At this time, the price is 99 yuan. How much is the original price

99÷（1-10%）÷（1+10%）
=110÷110%
=100 yuan
A: the original price is 100 yuan

Square of X + 6x-2 = () square + ()

(x+3)
(-11)

First question 45.5 ° + 31 ° 42'56 ″
Question 2 125 ° - 64 ° 24'37 ″
Question 3 52 ° 36 ′ 12 ″ x2-62 ° 35 ′ 54 ″ 6

The first question is 45.5 ° + 31 ° 42'56 ″ = 45 ° 30 '+ 31 ° 42'56 ″ = 76 ° 72'56 ″ = 77 ° 12'56 ″ the second question is 125 ° - 64 ° 24'37 ″ = 124 ° 59'60 ″ - 64 ° 24'37 ″ = 60 ° 35'23 ″ the third question is 52 ° 36 ′

When a shopping mall carries out a sales promotion, it gives a 20% discount to a product priced at 80 yuan, and then sells it at a 20% discount. What is the current price of the product?

The current price is 80 × 0.8 × 0.8 = 51.2 yuan
0.8 is 20% off

Expressed by scientific notation: 0.000359 ≈______ (keep two significant numbers)

0.000359≈3.6×10-4．