1. Model with mathematics. 2. Look for and express regularity in repeated reasoning. 3. Apply properties of operations as strategies to multiply and divide rational numbers. 4. Solve real-world and mathematical problems involving the four operations with rational numbers. 5. Solve multi-step real-life and mathematical problems posed with positive and negative rational numbers in any form (whole numbers, fractions, and decimals), using tools strategically. Apply properties of operations to calculate with numbers in any form; convert between forms as appropriate; and assess the reasonableness of answers using mental computation and estimation strategies. 6. Solve real-world and mathematical problems involving area, volume and surface area of two- and three-dimensional objects composed of triangles, quadrilaterals, polygons, cubes, and right prisms.