First grade answer:

Every time six children shake hands, there will be one less person, that is, one less handshake.

Then the formula is: 5+4+3+2+1=15;

A: Six children shake hands every two, shaking hands every * * * 15 times.

Learned multiplication and division answer:

You can use the rule: (the number of handshakes of the first child+the number of handshakes of the last child) × the number of handshakes in turn ÷2.

And get:

(5+ 1)×5÷2=6×5÷2=30÷2= 15。

Primary school mathematics is to teach children a series of knowledge about number, four operations, the calculation formula of figure and length, unit conversion and so on through textbooks, which lays a good mathematical foundation for junior high school and daily life calculation. Frieden Noel, a Dutch educator, said: "Mathematics comes from reality and must be rooted in reality and applied to reality." Indeed, modern mathematics requires us to observe the world from a mathematical perspective and explain the world in mathematical language. Judging from the mathematics learning psychology of primary school students, the learning process of students is not a passive absorption process, but a reconstruction process based on existing knowledge and experience. Therefore, learning while doing and learning while playing will make children learn more actively. From our educational goal, while imparting knowledge, we should pay more attention to cultivating students' comprehensive ability of observation, analysis and application.