1, fill in the blanks.
In the "wide angle of mathematics" in the second grade of primary school, there is a lesson "reasoning", the content of which is to let students fill in numbers on a square piece of paper, and it is required that the same numbers cannot appear in each row and column. This content exercises children's logical analysis ability and spatial ability.
2. Answering skills
That is, in a large grid, there must be four numbers 1, 2, 3 and 4 in each row and column, which cannot be repeated. Numbers in each row and column can only appear once. Ask the children to find out how much A and B are filled in respectively.
Guide children to find a key starting point. First, find the row or column with the most numbers. Among these rows or columns, which row and column with spaces has three different numbers? (Rows or columns with only one number are not considered). After confirmation, you can fill in this space first, and then fill in the remaining spaces and the specified spaces in the same way.
Extended data:
1, Overview of Primary School Mathematics
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.
2, primary school mathematics content
Numbers include integers, natural numbers, positive numbers, negative numbers, fractions, decimals and percentages. Counting units and numbers include counting units, numbers and decimal notation. The comparison of numbers includes the comparison of integer sizes: the difference between two integers has a regular value, the former is greater than the latter, and the negative number is the opposite. The nature of number includes the basic nature of fraction, the basic nature of decimal, and the law of decimal size change caused by decimal position movement.