2. One minus one is not zero. (type a word), answer: three. Seven eighths. (To use an idiom), the answer: seven ups and eight downs. Second, interesting topics Puccio is a famous mathematician in the former Soviet Union. 195 1 wrote a book, Math Teaching Methods in Primary Schools. There is an interesting question in this book. This shop sold 1026 meter cloth in three days. The sales volume of the second day is twice that of the first day; On the third day, it sold three times as much as the next day. How much rice cloth do you want to sell in three days? The first day 1 serving; The second day is twice as much as the first day; The third grade is three times that of the second grade, and the first grade is 2×3 times. Comprehensive calculation shows that the number of cloth sold on the first day is1026 ÷ (l+2+6) =1026 ÷ 9 =114 (meters) and1/kloc-.
3. Mathematical sayings Mathematics is an infinite science. -Herman Weil Mathematics is a theory that studies abstract structures. -Bourbaki School Mathematics is the mathematics that studies the quantitative relations and spatial forms in real life. -Engels Mathematics is the highest form of all knowledge. -Plato's mathematics is a unique art-halmos's mathematics is a constantly developing culture. -Oscar Wilde Mathematics is a rational spirit, which can make human thinking be applied to the most perfect degree. Klein, no matter how abstract any branch of mathematics is, will be applied to the real world one day. Lobachevsky