The relationship between positive proportion and negative proportion is an important knowledge point in the sixth grade of primary school. First of all, let students understand the significance of positive proportional relationship and inverse proportional relationship. The concepts in the book are wordy and verbose, which makes it difficult for students to remember.
Simple summary:
Simple summary: two related quantities, one quantity changes, the other quantity changes, and the ratio of the two quantities remains unchanged. In this way, the two quantities are proportional, y: x = k (certain); Two related quantities, one quantitative change, the other quantitative change, and the product of the two quantities remains unchanged. So the two quantities are inversely proportional, XxY=k (certain).
The meaning of positive and negative ratio:
The significance of positive proportion:
Two related quantities, one of which changes and the other changes with it. If the ratio of the corresponding two numbers in these two quantities is certain, these two quantities are called proportional quantities, and their relationship is called proportional relationship. If the letters X and Y are used to represent two related quantities and the letter K is used to represent their ratio (certain), the positive proportional relationship can be expressed as: y/x=k (certain).
The meaning of inverse proportion:
Two related quantities, one variable and the other variable. If the product of the corresponding two numbers in these two quantities is certain, these two quantities are called inverse proportional quantities, and their relationship is called inverse proportional relationship. If the letters X and Y are used to represent two related quantities and K is used to represent their products, the inverse relationship can be expressed as: X Y = K (certain).