NATIONAL STANDARDS MATHEMATICS (grades 3-5 and 6-8) Principles and Standards for School Mathematics (Standards 2000 Project) come from the National Council of Teachers of Mathematics. Source: http://www.education-world.com/standards/national/math/index.shtml NM-NUM.3-5.1 UNDERSTAND NUMBERS, WAYS OF REPRESENTING NUMBERS, RELATIONSHIPS AMONG NUMBERS, AND NUMBER SYSTEMS understand the place-value structure of the base-ten number system and be able to represent and compare whole numbers and decimals; NM-NUM.3-5.3 COMPUTE FLUENTLY AND MAKE REASONABLE ESTIMATES develop fluency with basic number combinations for multiplication and division and use these combinations to mentally compute related problems, such as 30x50; develop fluency in adding, subtracting, multiplying, and dividing whole numbers; develop and use strategies to estimate the results of whole-number computations and to judge the reasonableness of such results; develop and use strategies to estimate computations involving fractions and decimals in situations relevant to students' experience; use visual models, benchmarks, and equivalent forms to add and subtract commonly used fractions and decimals; select appropriate methods and tools for computing with whole numbers from among mental computation, estimation, calculators, and paper and pencil according to the context and nature of the computation and use the selected method or tools. NM-NUM.6-8.1 UNDERSTAND NUMBERS, WAYS OF REPRESENTING NUMBERS, RELATIONSHIPS AMONG NUMBERS, AND NUMBER SYSTEMS work flexibly with fractions, decimals, and percents to solve problems; NM-NUM.6-8.3 COMPUTE FLUENTLY AND MAKE REASONABLE ESTIMATES select appropriate methods and tools for computing with fractions and decimals from among mental computation, estimation, calculators or computers, and paper and pencil, depending on the situation, and apply the selected methods;