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    • ▾2nd grade
      • ▸Add and subtract within 20
        • •Add to count rectangular arrays
        • •Mentally add and subtract within 20
      • ▸Place value
        • •Place value with hundreds
        • •Convert between various representations, numbers within 1000
        • •Counting and skip-counting within 1000
        • •Intro to even and odd
        • •Compare three-digit numbers
      • ▸Add and subtract within 100
        • •Mentally add and subtract within 100
        • •Add and subtract within 100, abstract
        • •One-step word problems, add and subtract within 100
        • •Two-step word problems, add and subtract within 100
      • ▾Add and subtract within 1,000
        • •Add and subtract within 1,000
        • •Add multiple two-digit numbers
        • •Mentally add or subtract powers of ten
      • ▸Money and time
        • •Money word problems, including dollars
        • •Tell and write time, five minute increments
      • ▸Measurement
        • •Compare lengths by measuring
        • •Estimate lengths
        • •Add and subtract within 100 to solve word problems involving lengths
        • •Add and subtract within 100 on the number line
      • ▸Data
        • •Plot measurements on a line plot
        • •Draw picture and bar graphs
      • ▸Geometry
        • •Partition rectangles into rows and columns
        • •Area of a rectangle by counting unit squares
        • •Partition circles and rectangles into equal shares
        • •Draw shapes with certain attributes
        • •Intro to tessellations
     › 2nd grade › Add and subtract within 1,000

    Add multiple two-digit numbers

    Add up to four two-digit numbers. Knowing that addition is commutative and associative means we can add in any order we like. By changing the order in which we add, we can sometimes make the problem easier to solve. For example, 37 + 25 + 13 can be rearranged to 37 + 13 + 25.

    Conclude by leading this investigation:

    Too Many Mice!
    by MathPickle

    2.NBT.B.6: Add up to four two-digit numbers using strategies based on place value and properties of operations.