Math: Adding and Subtracting

Adding and Subtracting with 2-Digit Numbers

• Computation
  • 2.4B add up to four two-digit numbers and subtract two-digit numbers using mental strategies and algorithms based on knowledge of place value and properties of operations
• Problem Solving
  • 2.4C solve one-step and multi-step word problems involving addition and subtraction within 1,000 [120 in this unit] using a variety of strategies based on place value, including algorithms
  • 2.4D generate and solve problem situations for a given mathematical number sentence involving addition and subtraction of whole numbers within 1,000 [120 in this unit].
• Representing
  • 2.7C represent and solve addition and subtraction word problems where unknowns may be any one of the terms in the problem

Counting Patterns (Suggested: 5 days)

• 2.5A determine the value of a collection of coins up to one dollar [pennies, nickels, and dimes only in this unit]
  • 2.5B use the cent symbol, dollar sign, and the decimal point to name the value of a collection of coins
• RRISD 2.7B Skip count forward and backward by ten and one hundred from any given number up to 1,000

Developing Strategies for Adding and Subtracting (Suggested: 18 days)

• 2.4A recall basic facts to add and subtract within 20 with automaticity [Including the Make-Ten Strategy for Addition; Including the Think Addition Strategy for Subtraction]

1st Grade Measuring Length and Telling Time  (Suggested: 15 days)

• 1.7D  Describe a length to the nearest whole unit using a number and a unit
  • 1.7A  Use [non-standard] measuring tools to measure the length of objects to reinforce the continuous nature of linear measurement
  • 1.7B  Illustrate that the length of an object is the number of same-size units of length that, when laid end-to-end with no gaps or overlaps, reach from one end of the object to the other
  • 1.7C  Measure the same object/distance with units of two different lengths and describe how and why the measurements differ
• 1.7E  Tell time to the hour and half hour using analog and digital clocks

1st Grade Creating, Solving, and Representing Story Problems (Suggested: 8 days)

• Computation
  • 1.3D Apply basic fact strategies to add and subtract within 20, including making 10 and decomposing a number leading to a 10
  • 1.5F Determine the unknown whole number in an addition or subtraction equation when the unknown may be any one of the three or four terms in the equation
  • 1.5G Apply properties of operations to add and subtract two or three numbers
• Problem Solving
  • 1.3B Use objects and pictorial models to solve word problems involving joining, separating, and comparing sets within 20 and unknowns as any one of the terms in the problem such as 2 + 4 =___; 3 +___= 7; and 5 =___– 3
  • 1.3F Generate and solve problem situations when given a number sentence involving addition or subtraction of numbers within 20
• Representing and Explaining
  • 1.3E Explain strategies used to solve addition and subtraction problems up to 20 using spoken words, objects, pictorial models, and number sentences
  • 1.5D Represent word problems involving addition and subtraction of whole numbers up to 20 using concrete and pictorial models and number sentences
  • 1.5E  Understand that the equal sign represents a relationship where expressions on each side of the equal sign represent the same value(s)

Counting Quantities (Suggested: 2 days, using both numeracy and spiral review time)

• RRISD 2.1 organize and count a collection of objects and create a recording of how the objects were counted
  • 2.1C  select tools, including real objects, manipulatives, paper and pencil, and technology as appropriate, and techniques, including mental math, estimation, and number sense as appropriate, to solve problems;
  • 2.1E  create and use representations to organize, record, and communicate mathematical ideas;