Grade 5 - Number
Standard 5.N.11 - Solve addition and subtraction word problems with decimals.
Included Skills: Decimals, Mixed Equations
Demonstrate an understanding of addition and subtraction of decimals (to thousandths), concretely, pictorially, and symbolically, by • using personal strategies • using the standard algorithms • using estimation • solving problems • Estimate a sum or difference using front-end estimation (e.g., for 6.3 + 0.25 + 306.158, think 6 + 306, so the sum is greater than 312) and place the decimal in the appropriate place. • Correct errors of decimal point placements in sums and differences without using paper and pencil. • Explain why keeping track of place value positions is important when adding and subtracting decimals. • Predict sums and differences of decimals using estimation strategies. • Solve a problem that involves addition and subtraction of decimals, to thousandths. • Model and explain the relationship that exists between an algorithm, place value, and number properties. • Determine the sum and difference using the standard algorithms of vertical addition and subtraction. (Numbers are arranged vertically with corresponding place value digits aligned.) • Refine personal strategies, such as mental math, to increase efficiency when appropriate (e.g., 3.36 + 9.65 think, 0.35 + 0.65 = 1.00, therefore, 0.36 + 0.65 = 1.01 and 3 + 9 = 12 for a total of 13.01)