Math for 9 Year Olds: What Your Child Should Know

What Your 9-Year-Old Will Learn in Math

Number and Operations in Base Ten

A 9-year-old student should know how to read, write and compare multi-digit whole numbers using numerals (48), word form ('forty-eight') and expanded form (40 + 8). Your child must also use place value to round multi-digit numbers to any specified place. In the fourth grade math curriculum, your child will know how to fluently add and subtract multi-digit whole numbers, as well as how to multiply a whole number of up to four digits by a 1-digit whole number. Lastly, your child should know how to find whole number quotients and remainders for 1-digit divisors and up to 4-digit dividends.

Operations and Algebraic Thinking

Within this focus area, your 9-year-old should know how to multiply or divide to solve real-world problems that involve comparisons. Your child should also be able to solve multi-step word problems that contain whole numbers and that require him or her to use addition, subtraction, multiplication and division. Often, these problems will have remainders that your child must also interpret. Your fourth grader will learn to find factor pairs for all whole numbers up to 100 and to create patterns using provided numbers or shapes.

Number and Operations - Fractions

Your 9-year old should know how to add and subtract mixed numbers with like denominators, as well as how to compare two fractional amounts that have different numerators or different denominators. In the fourth grade, your child will be solving word problems that require him or her to add or subtract fractions with like denominators. Your fourth grader will also need to know how to multiply a fraction by a whole number to solve a real-world problem. Within this focus area, your student will also learn to use a decimal notation for a fraction with a denominator of ten or 100 and to compare two decimal amounts up to the hundredths place.

Measurement and Data

Your child should be able to use addition, subtraction, multiplication and division to solve real-world problems involving time, money, distance, mass and volume. Your 9-year-old must also know how to relate different units of measurement within a system based on their size. It will be important for your child to know how angles are formed and to be capable of measuring angles using a protractor. Finally, your child must know - and use - the formulas to determine the area and perimeter of a rectangle.

Geometry

At the fourth grade level, your child should identify a line of symmetry for a given figure. Your 9-year-old should also identify right triangles and classify 2-dimensional figures based on provided characteristics, such as angle size. Your child will know how to draw lines, line segments, rays, angles, points, perpendicular lines and parallel lines. Lastly, be sure your child can identify each of these geometric features within a 2-dimensional figure.