How to do math problems well, how to do math problems well?

18 square decimeters = square meters.

The volume of this stone v = cubic meters = 810 cubic decimeters.

This stone weighs 810*2=1620 kg.

Volume: 18 * cubic decimeters).

810*2=1620 (kg).

Volume cubic meters weigh 1620 kg.

18 square decimeters = square meters.

Volume = cubic meters. Weight =

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f'(x) = 3x -6x-9 = 3 (x - 3) (x + 1) let f'(x)=0, x=3 or -1

f(x) increases monotonically in the interval (- 1) (3,+) and decreases monotonically in the interval [-1,3].

So f(x) achieves a maximum value of 10 at x=-1

A minimum value of -22 is obtained at x=3

The example questions that the teacher has talked about must be done, the foundation is very important, as for the difficult and strange questions, you have the energy to specialize, and you have no energy to give up, after all, the exam looks at the score, not the ability, and the score of the problem is very small.

First of all, you can't spend more than 1 hour on choice and fill-in-the-blank questions, preferably around 45 minutes.

Secondly, the first four questions of the big question are all points, and most students can get a lot of points, so you have to make sure that the first four questions lose as few points as possible. The next few questions, write as much as you can. For example, some simple calculation of the general term formula problem or the derivative step of the series must be grasped well.

It may be helpful to read more examples from the book, and it is important to return to the textbook. There will be a lot of analysis and thinking about the good way on the example questions, and the state lead is very helpful for the solution of similar questions. Learn to draw inferences from one to the other in practice, and then return from three to one, so that you can master many rules.

There are 64 squares on the chess board, so the last one puts 2 63 = 9223372036854775808 grains.

Taking rice as an example, about 600 grains of ordinary northern rice is 50 grams, and this kind of rice is high-quality rice with full grains.

Then, a grain of rice is one-twelfth of a gram.

Well, 2 63 grains of rice weigh about 768614336404564651 grams.

That's 768614336404565 kilograms.

7686143364045 tons.

That's more than 7,686.1 billion tons.

China's total grain output in 2007 was about 500 million tons.

You see why it's not enough, right?

In reality, there are generally 8 eggs per catty.

That is, about 62 grams of an egg.

1. Start by taking a pack of noodles and placing 1 to 2 eggs on each end of the scale.

Get one egg that is lighter than one pack of noodles, and two eggs that are heavier than one pack of noodles.

2, again, take two packs of noodles and 3 eggs on both ends of the scale, the noodles may be slightly heavier, 3, finally, take 3 packs of noodles and 5 eggs on both ends of the balance, the eggs may be slightly heavier, then, from 2, 3 can be deduced 5 packs of noodles 8 eggs, finally, expand the weight of 5 packs of noodles by 10 times, get 80 eggs 5kg

Of course, it is impossible to get an accurate result on this question.

Let's weigh how many eggs are in 300 grams, and if there are x eggs in 300 grams, then one egg is.

300 x grams, so that you can calculate how many eggs there are in 5 kg.

5000/(300/x)=.

Set x eggs for 200 grams.

Take two packets of instant noodles and place them on one end of the scale.

Put the eggs on the other end, and when the balance is level, the pile of eggs is 200 grams.

Then divide five thousand by two hundred to equal 25

25 times x is the number of eggs in five kilograms.

Take a bag of instant noodles first, then put the eggs to see how many eggs are equal to 100 grams of instant noodles, and multiply by 500

Not necessarily, but that's what I think!