What new concept begins in fifth grade place value?

Beginning work with decimals is the correct answer because fifth grade serves as a pivotal point in the mathematics curriculum where students expand their understanding of the base-ten number system. At this grade level, students transition from whole numbers to a more complex representation of numbers, which includes decimal notation. They learn how decimals relate to fractions, enhancing their comprehension of place value by recognizing that tenths, hundredths, and thousandths are integral parts of the numeric system.

In fifth grade, students also start performing operations involving decimals, which builds on their previous knowledge of whole numbers while introducing new concepts such as rounding and comparing decimal quantities. This foundation is crucial for further mathematical concepts they will encounter in later grades, such as working with ratios and percentages.

Other options, such as the integration of algebraic thinking, working with fractions, and statistics and probability, are components of the curriculum, but they typically do not represent the unique introduction or shift in understanding that decimals do for fifth graders, making starting work with decimals distinctly significant during this educational stage.