1. It's still raining after school at noon, and everyone is looking forward to sunny days. Xiaoming said to Xiaoying, "It has been raining for three days. Do you think it will be sunny in 36 hours? "

Answer analysis: no. Because it is night.

Aunt Zhang and Aunt Li bought a basket of apples, one of which was 20 kilograms. Aunt Zhang took out 10 kg from the basket, and the empty basket weighed 1 kg. How many Jin did Aunt Li buy? How many grams?

Answer analysis: Apple bought by Aunt Li: 20- 10- 1=9 (kg), 1000 g× 9 = 9000 g A: Aunt Li bought 9 kg of apples, that is, 9000g.

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Mathematical language is also difficult for beginners. How to make these words have more accurate meanings than everyday language also puzzles beginners. For example, the words "open" and "domain" have special meanings in mathematics.

Mathematical terms also include proper nouns such as embryo and integrability. But these special symbols and terms are used for a reason: mathematics needs accuracy more than everyday language. Mathematicians call this requirement for linguistic and logical accuracy "rigor".