Length unit conversion:

1， 1 km = 1000 m， 1 m = 10 DM， 1 DM = 10 cm， 1 m = 100 cm，65438。

2. A pencil is 20cm long, a pencil box is10mm thick, a math book is 6mm thick, and a person is100cm high.

People walk 70 meters per minute, and planes, ships, trains and cars walk 80 kilometers per hour.

Weight unit conversion:

1, 1 ton = 1000 kg, 1 kg = 1000 g, 1 kg = 1 kg.

2. Chickens, ducks and geese weigh grams, people, dogs, cows and pigs weigh kilograms, and elephants and sharks weigh tons.

Currency unit conversion:

1, RMB unit conversion: 1 yuan = 10 angle, angle = 10 minute, 1 yuan = 100 minute.

Time unit conversion:

1, 1 century = 100, 1 year =65438+ February, and the big month (3 1 day) has13578106558.

2. 1 day =24 hours, 1 hour =60 minutes, 1 minute =60 seconds, 1 hour =3600 seconds.

Operation method:

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

2.65438 multiple +0 × multiple = multiple, multiple ÷ 1 = multiple, multiple ÷ multiple = 1.

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

4. Unit price × quantity = total price, total price/unit price = quantity, total price/quantity = unit price.

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

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

7. The minuend-subtrahend = difference, the minuend-difference = subtrahend, and the difference+subtrahend = minuend.

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

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

Mathematical concept of 1-3 level;

1, two digits divided by one digit: divide by ten digits first, then divide by four digits, and the remainder of each division is less than the divisor. Division can be tested by multiplication. No residue: quotient× divisor = dividend; Having a remainder: quotient × divisor+remainder = dividend.

2. 10 one is ten, 10 ten is one hundred, 10 one hundred is one thousand, 10 one thousand is ten thousand.

3. From the right, the first place is a unit, the second place is ten, the third place is one hundred, the fourth place is one thousand, and the fifth place is ten thousand. Four digits consist of thousands, hundreds, tens and ones.

4. Four-digit writing: write from top to bottom, write a few digits, and write 0 if there are no digits. How to read four digits: starting from the high place, there are 1 zeros in the middle or several zeros in succession, all of which are read-only, and none of the zeros at the end are read.

5, the size of the comparison number: different digits, more digits; The number of digits is the same as the thousand digits; A thousand is the same as a hundred; A hundred is the same as ten; Ten digits are the same before comparing sizes.

6. To accurately measure the weight of an item, please use a "scale" to weigh it. Weigh the weight of general goods, usually in kilograms; Lighter items are usually measured in grams. The kilogram is represented by the symbol "kg" and the gram is represented by the symbol "g". 1 kg =1000g.

7. Both a rectangle and a square have four sides and four corners, which are quadrangles. The opposite sides of a rectangle are equal, and all four corners are right angles. All four sides of a square are equal, and all four corners are right angles. A square is a special rectangle.

8. The total length of a plane figure in one week is the perimeter. Girth of rectangle =2 length +2 width or girth of rectangle = (length+width) ×2 length of rectangle = girth ÷2 width of rectangle = girth ÷2 girth of long square = side length ×4 side length of square = girth ÷4 Cut the largest square in rectangle as long as the side length = width.

9.24-hour time words include: morning, morning, morning, noon, afternoon, evening, etc. A. Ordinary timekeeping method →24-hour timekeeping method: remove the time word, and add the time word with+12B and 24-hour timekeeping method → ordinary timekeeping method. When it exceeds 12, it is important to-12C. For the required elapsed time, you can unify the timing method first, and then subtract the previous time from the later time to change the result into time units.

10, observe the object. When you look at a long (regular) cube from different angles, you can see at most three faces.

1 1. Understand the meanings of words such as "occasionally", "frequently", "possibly" and "definitely", and take these words as examples.

Extended data:

Characteristics of error formula

1 claims to be scientific, but it is vague and lacks tools.

2. Operation definitions (for example, public variables, ownership or objects that outsiders can also check) cannot be used.

3, can not meet the principle of simplicity, that is, when many variables appear, can not get the answer from the simplest way.

4. Use ambiguous language and a lot of technical terms to make the article look scientific.

5. Lack of boundary conditions: rigorous scientific theory clearly defines in a limited scope, and clearly points out when and where the prediction phenomenon is applicable and when and where it is not applicable.