What is the level of iv?

IV is a Roman numeral, which was used in Europe before Arabic numerals (actually Indian numerals) were introduced, but it is rarely used now. It came into being later than China's figures and Oracle Bone Inscriptions's, and even later than Egyptian decimal figures.

Roman numerals have the following seven basic symbols: I( 1), V(5), X( 10), L(50), C( 100), D(500), M( 1000). Roman numerals and decimal numerals have different meanings. They have no number representing zero and have nothing to do with the carry system. So people at that time said that 0 was represented by (spaces).

Roman numeral group numbering rules:

1, any one of the basic numbers I, X and C, alone or to the right of a large number, cannot exceed three; Only one can be used on the left side of a large number.

2. You can't put any of the basic numbers V, L and D on the left side of a large number as a decimal and form a number by subtraction; Put it on the right of a large number and add it to form a number. Only one can be used.

3. The small numbers to the left of V and X can only be used as Ⅰ.

4. the small number to the left of l and c can only be X.

5. the small number to the left of d and m can only be C.

In the weather intensity standard, the level IV is general warning, and the level is blue.