The rule of rounding faster, the accuracy of a number depends on the last digit of this number, the last digit of 50000 is 5, accurate to 10000, and the last digit of 52000 is 0, accurate to one place.

Second, the calculation method is different:

Approximate number in ten thousand, calculate the original maximum number and minimum number, and then compare them.

According to the rounding rule, 50,000 is accurate to 1 10,000 digits. According to the rounding rule, if you look at the number on thousands, the largest number is no carry, which is 4. It doesn't matter if the following figures are rounded off, so take 9, which is 54999. The minimum is carry 5, and the following numbers do not affect carry, and the minimum is 0, so this number is 45000.

Third, the definition is different:

A shortcut to add up the same numbers. The result of its operation is called product, and "X" is the symbol of multiplication. From the philosophical point of view, multiplication is the result of qualitative change caused by additive quantity. The multiplication of integers (including negative numbers), rational numbers (fractions) and real numbers is a systematic summary of this basic definition.

Multiplication principle: If there is a direct proportional relationship between the dependent variable F and the independent variables x 1, x2, x3, xn, and each independent variable is qualitatively different, then it is meaningless to lack any independent variable F..

Extended data:

When using scientific computers for construction work, we often encounter such a situation: sometimes there are several decimal points on the left side of the integer of the answer.

For example, short side 255 divided by long side 1005 = tan 0.438+03.

Similar to this situation, it will be more complicated to calculate the size and side with these decimal points as reference tan values. So in order to properly remove similar decimal points without affecting the actual dimensional accuracy, I will introduce the rounding calculation method in mathematics here.

Usually, carpenters come into contact with the drawings in metric system, and the area of the drawings is in millimeters (mm), ranging from tens of millimeters to more than ten or twenty meters. As long as the decimal point is appropriately deleted according to the actual size, and the error is less than one millimeter, the rounding method should be implemented.

In millimeters, if it is in the third place, we will round it off in the fourth place. Look at the fourth place first: if it is 4 or less, we will discard it; If it is 5 or greater, it is also discarded, but 1 should be added to its left cell. This method is called rounding.

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