1. Mixed Operations with Natural Numbers
① Calculations involving addition and subtraction
② Calculations involving multiplication and division
③ Calculations involving addition, subtraction, and multiplication
④ Calculations involving addition, subtraction, and division
⑤ Calculations involving addition, subtraction, multiplication, and division

2. Factors and Multiples
① Factors
② Multiples
③ Relationship between factors and multiples
④ Common factors and the greatest common factor
⑤ How to find the greatest common factor
⑥ Common multiples and the least common multiple
⑦ How to find the least common multiple

3. Correspondence Relationship
① Correspondence relationship between two quantities
② Expressing correspondence relationships as equations
③ Finding and expressing correspondence relationships in real life as equations

4. Reducing and Common Denominators
① Fractions of the same value
② Creating fractions of the same value
③ Reducing fractions
④ Common denominators
⑤ Comparing the size of fractions
⑥ Comparing the size of fractions and decimals

5. Addition and Subtraction of Fractions
① Adding proper fractions with a sum less than 1
② Adding proper fractions with a sum greater than 1
③ Adding mixed numbers
④ Subtracting proper fractions
⑤ Subtracting mixed numbers where the fractional parts can be subtracted
⑥ Subtracting mixed numbers where the fractional parts cannot be subtracted

6. Perimeter and Area of Polygons
① Perimeter of regular polygons
② Perimeter of rectangles, parallelograms, and rhombuses
③ Unit of area: 1 ㎠
④ Area of rectangles
⑤ Units of area larger than 1 ㎠
⑥ Area of parallelograms
⑦ Area of triangles
⑧ Area of trapezoids
⑨ Area of rhombuses