Common Core State Standards for Mathematics Standards for Mathematical Practice [K-12] Use appropriate tools strategically. [K-12] Attend to precision. [K-12] Look for and make use of structure. [K-12] Look for and express regularity in repeated reasoning. [K-12] Operations and Algebraic Thinking [K - 5] Gain familiarity with factors and multiples.  4. Find all factor pairs for a whole number in the range 1—100. Recognize that a whole number is a multiple of each of its factors. Determine whether a given whole number in the range 1—100 is a multiple of a given one-digit number. Determine whether a given whole number in the range 1—100 is prime or composite.  Measurement and Data [K - 5] Geometric measurement: understand concepts of angle and measure angles.  7. Recognize angle measure as additive. When an angle is decomposed into non-overlapping parts, the angle measure of the whole is the sum of the angle measures of the parts. Solve addition and subtraction problems to find unknown angles on a diagram in real world and mathematical problems, e.g., by using an equation with a symbol for the unknown angle measure.  Geometric measurement: understand concepts of volume and relate volume to multiplication and to addition.  4. Measure volumes by counting unit cubes, using cubic cm, cubic in, cubic ft, and improvised units.  5. Relate volume to the operations of multiplication and addition and solve real world and mathematical problems involving volume.  b. Apply the formulas V = l × w × h and V = b × h for rectangular prisms to find volumes of right rectangular prisms with whole-number edge lengths in the context of solving real world and mathematical problems.  Number and Operations—Fractions [3 - 5] Develop understanding of fractions as numbers.  1. Understand a fraction 1/b as the quantity formed by 1 part when a whole is partitioned into b equal parts; understand a fraction a/b as the quantity formed by a parts of size 1/b.  3. Explain equivalence of fractions in special cases, and compare fractions by reasoning about their size.  a. Understand two fractions as equivalent (equal) if they are the same size, or the same point on a number line.  b. Recognize and generate simple equivalent fractions, e.g., 1/2 = 2/4, 4/6 = 2/3). Explain why the fractions are equivalent, e.g., by using a visual fraction model.  c. Express whole numbers as fractions, and recognize fractions that are equivalent to whole numbers. Examples: Express 3 in the form 3 = 3/1; recognize that 6/1 = 6; locate 4/4 and 1 at the same point of a number line diagram.