The emphsis in this section in on area of rectangles, parallelograms, and triangles. USe of graph of dot paper will help develop the concepts involved in determining area, so that formulas can be taught with meaning. Decimals are introduced by relating them to fractions that have denominators of 10 or 100. Extension of place value to thousandths is emphsized. The problem-solving section features material where there is enough information or too much information to solve a problem.
Place value is extended to ten-thousandths.
Multiplication of decimals is built on estimating products. After the rule for placing the decimal point has been established, rounding and estimating products is used to check answers. Special attention is given to multiplying by powers of ten and applying this to the conversion of metric units and mental computation. Division of decimals is developed in very small steps which build on extending concepts of number estimation, approximation, and mental computation. The problem solving lesson applies reasoning to determine whether the remainder should be given as a whole number, a fraction, or a decimal.