Thinking of writing: You can choose to draw a fan-shaped statistical chart of Party A, Party B and Party C's donations to the disaster area, namely 15 yuan, 27 yuan and 18 yuan. You should write a 200-word math diary and talk about your feelings according to the process of making the fan-shaped statistical chart.

Text:

To make a fan-shaped statistical chart, we must first make clear the percentage of each person's donation to the total donations of three people and three people, and the degree of the central angle of the corresponding fan.

Three donations: 15+27+ 18=60 (RMB),

The percentage of a's donation to the three donations is:15 ÷ 60 = 25%;

The percentage of Party B's donation to the three donations is: 27 ÷ 60 = 45%;

The percentage of C's donation to the three donations is: 18 ÷ 60 = 30%.

The degrees of the central angle of the sector representing the number of donations made by the three people are respectively:

360 ×25%=90 ;

360 ×45%= 162 ;

360 ×30%= 108 。

The key to making a fan chart is to find the degree of the central angle of each fan. The sector statistical chart represents the total with a whole circle, and the size of each sector in the circle represents the percentage of each part in the total. The relationship between the number of each part and the total number can be clearly expressed through the fan-shaped statistical chart.

Use the area of the whole circle to represent the total number, and use the sector area of the circle to represent the percentage of each part in the total number; The function is to clearly reflect the relationship between the number of parts and the total number; The relationship between the sector area and its corresponding central angle is as follows: the larger the sector area, the greater the degree of the central angle; The smaller the sector area, the smaller the degree of the central angle.