5.NOS.B.6: Apply and extend previous understanding of addition and subtraction of whole numbers to add and subtract decimals to hundredths. a. Apply estimation strategies to estimate sums and differences of decimals. b. Use concrete models, drawings, strategies based on place value (e.g., partial sums), properties of operations and/or the inverse relationship between addition and subtraction to add and subtract decimals. c. Use an algorithm to add and subtract decimals. d. Determine and explain when a strategy or algorithm is most efficient.