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    • ▾4th grade
      • ▸Place value of whole numbers
        • •Place value of multi-digit whole numbers
        • •Adding and subtracting multi-digit numbers
        • •Multiply and divide by 10
        • •Represent a number using base ten blocks, units, tens, and hundreds
        • •Convert between written forms of numbers
        • •Round whole numbers
        • •Estimating sums and differences by rounding
        • •Estimating products by rounding
      • ▸Multiplication and division
        • •Multiplying one-digit numbers by 10, 100, and 1000
        • •Multiplying one-digit numbers by multiples of 10, 100, and 1000
        • •Multiplying 10s
        • •Multiplication
        • •Quotients and remainders
        • •Pattern in the units digit of multiples
        • •Solve multiplication and division word problems
        • •Multi-step word problems
      • ▸Factors, multiples, and patterns
        • •Factors and multiples
        • •Divisibility tests
        • •Prime and composite numbers
        • •Number patterns
      • ▸Equivalent fractions and comparing fractions
        • •Equivalent fractions
        • •37 trick
        • •Compare fractions with unlike numerators, denominators, or both
      • ▸Fraction arithmetic
        • •Round fractions
        • •Add and subtract fractions with like denominators
        • •Add fractions with denominators of 10 or 100
        • •Multiply fractions by whole numbers
      • ▸Understand decimals
        • •Represent decimal numbers using base ten blocks
        • •Compare decimals to hundredths
      • ▾Geometry
        • •Intro to parallel and perpendicular lines
        • •Lines of symmetry
        • •Rotational symmetry
        • •Intro to angles
        • •Measuring and drawing angles
        • •Coterminal angles
        • •Naming angles
        • •Adjacent angles and the additive property of angles
      • ▸Units of measurement
        • •Converting larger units of volume to smaller ones
        • •Converting larger units of length to smaller ones
        • •Converting larger units of time to smaller ones
        • •Word problems involving measures
     › 4th grade › Geometry

    Lines of symmetry

    First, students will see examples of bilateral symmetry in nature, and other lines of symmetry in nature, such as lines of symmetry in starfish. Recognize bilateral symmetry in nature. Recognize lines of symmetry by folding paper and using mirrors. Identify bilateral symmetry and draw the line of symmetry.

    Intro to reflective symmetry by Khan Academy

    Identify line symmetry by Khan Academy

    Conclude by leading this investigation:

    Siteswap (juggling number patterns)
    by MathPickle

    4.G.A.3: Recognize a line of symmetry for a two-dimensional figure as a line across the figure such that the figure can be folded along the line into matching parts. Identify line-symmetric figures and draw lines of symmetry.

    Lessons and practice problems