Research On Test Questions Of Drawing With No Scale Ruler In The Grid Diagram In Junior High School Mathematics

With the promulgation of the “Double reduction” policy and the “Compulsory Education Mathematics Curriculum Standard(2022)edition”,more attention has been paid to the teaching of mathematics in junior high schools.According to the requirements of the new curriculum standard,students need to master five different types of ruler and gauge drawing in junior middle school.Ruler and gauge drawing is an important part of geometry,in its inspection form,many areas have chosen non-scale ruler mapping as a carrier for the problem.Non-scale ruler drawing is the extension and development of ruler drawing,which plays an important role in examining students’ ability of logical reasoning and geometric intuition.The purpose of this paper is to discuss the problem of ruler without scale mapping in grid mapping under the background of the "double subtraction" policy.Examination knowledge points and examination methods of graph questions,explore the diversity of different test questions solving steps,disassemble it into several basic graphs and advanced graphs,and analyze the graphing principles of each step in detail to provide reference for students and teachers,it can provide help in the drawing problems in the review stage of the ninth grade high school entrance examination,decompose complex problems into several basic and easy-to-use problems,reduce the burden of students in learning grid drawing,and enhance students’ confidence.The main research results include the following aspects:(1).The problem of ruler without scale drawing in grid diagrams can only be solved by selecting points and connecting straight lines.Compared with ruler and ruler drawing,the compass tool is missing,and arcs cannot be drawn,and line segments of a specific length cannot be made.,because the grid diagram is composed of small squares with a size of 1.The unit length is provided,and there are basic positive integer line segments,which can be obtained by connecting grid points;2.The vertical and parallel positional relationship is provided,which is It provides important conditions for making complex graphics,(2).Most of the mapping problems can be attributed to 4 kinds of basic mapping,1.Make line segment points;2.Make translation transformation;3.Make vertical lines;4.Make parallel lines.And 5 kinds of advanced drawing,1.Making isometric and rotating graphs;2.Making axisymmetric graphs;3.Making isometric line segments;4.Making angles of specific trigonometric function values;5.Drawing involving geometric maxima.Line segment points are the most important drawing methods,and skilled use of X-type similarity and A-type similarity is the basis for solving complex problems.(3).The principles behind each drawing model come from textbooks,such as congruence and similarity,among which the properties of parallelograms and similar triangles are the most commonly used knowledge points for grid drawing.The key content of the examination of grid mapping.