Solve a 6th grade math problem, solve a 6th grade math problem

Throw the 1 first, and multiplying 1 by any number has no effect on the result.

First, look at the numbers within 100.

From 2-10 onwards, notice that if there is a 2x5, there will be a zero.

So how many 2x5s are there within 100? There should be a pair every 10 numbers.

So within 100 there are a total of 10 2x5 0s, plus . . . 90 produces 9 zeros

So within 100, there are a total of 19 0s, plus two zeros of 100, a total of 21 zeros, multiplied from 2 to 1000, there should be 10 units like 100, so it is 210 zeros, but note that 1000 is 3 zeros, so multiplying from 2 to 1000 is a total of 211 zeros, the same is true. From 1001 to 2000, there should also be 211 0s, and from 2001 to 2008, there is a pair of 2x5, which is a 0, so the total number of consecutive 0s is 211 + 211 + 1 = 423.

You don't need to look at the others, just look at 2, 5, 10, 12, 15, 20, 22, 25, 30 ......2000, 2002, 2005 on it, 2, 5, 10 are two 0s, 12, 15, 20, and two ,...... again1992, 1995, 2000 and two more 0, 2002, 2005 is one! And 10 to 2000 has 200, multiply 2 to 400, and there is one more behind, so there are 401 0s in total!

There are 201 zeros in total.

The mantissa should be counted with 5 and 2 and 0.

Xie Xuan Song teased the answer to Zheng:

The total surface area of the classroom is calculated (8 6 6 4 8 4) 2 208 (square meters), and then the area that needs to be painted is 208 square meters after deducting the square meters that do not need to be painted).

20 2 2 16 (cm), 10 2 2 6 (cm), so the volume is 16 6 2 192 (cubic centimeters).

18 2 3 3, 12 2 2 3, 24 2 2 2 3, then there are three factors of the same impact. So the cuboid volume is 2 3 4 24 (cubic centimeters of virtual hole meters).

The volume of the steel pipe is cubic decimeter), so the length of the steel pipe is 9 10; ÷6²；250 (decimeter) 25 (meter).

Analysis: (1) The first time I bought furniture with a price of 2,600 yuan, because it did not exceed 3,000 yuan, I did not enjoy the discount;

2) First find the second payment of 4320 yuan, how much is the original price of the furniture bought, and then find how much yuan should be paid for the one-time purchase of these furniture;

3) Find out how much yuan to save, and then according to the number of fractions of another number, use division to answer Answer: (1) The first time I bought the furniture with a price of 2600 yuan (2) If Xiaofeng's father buys these furniture at one time, he should pay 5920 yuan or 6400 yuan (3) Under the condition of (2), he can save 25 173 or 13 173 yuan compared with the original

A is 142 and B is 15

Let A be x and B be y

x=9y+7

x+y+9+7=173

Solution x=142

y=15