Page 77 1, 2, 3 and 4 are all positive numbers. -4, -3, -2,-1 are all negative numbers. 0, 1, 2, 3 and 4 are natural numbers. -4, -3, -2,-1, 0, 1, 2, 3, 4 are all integers. 1. All decimal ones are called decimal counting. 1, 10, 100, 1000, 10000 are all counting units. 2. Compare the sizes of two numbers, starting from the highest bit first, and then going from one level to another. 3. The basic nature of the fraction: the numerator and denominator are multiplied or divided by the same number at the same time (except 0), and the size of the fraction remains unchanged. Basic properties of decimals: Add "0" or remove "0" at the end of decimals, and the size of decimals remains unchanged. It can be converted into decimals through the basic properties of fractions, and it can also be converted into fractions through the basic properties of decimals. If the decimal point moves to the left, the number will decrease. When the decimal point moves to the right, the number expands. 5. Factor: The factor of a number is also called the divisor of this number. Multiplication: An integer can be divisible by another integer, which is a multiple of another integer. Prime number: Prime number is also called prime number. A natural number greater than 1 is called a prime number (also called a prime number) if there are no other factors except 1 and itself; a number in a natural number that can be divisible by other numbers except 1 and itself is called a composite number. 1' is neither a prime number nor a composite number. Do it: 27046 = 2x10000+7x1000+4x10+6x1taught by our teacher, purely original, typing word by word. Please adopt it. It's definitely not plagiarism, I promise my eighth ancestor! !