Grade 4 Math Flashcards: Angles — Acute, Right, Obtuse and Measuring

How to Present

• Print on card if possible, cut along the dashed lines.
• Use for matching, sorting, snap and memory games (see the Teacher Resources).
• Display on the word wall during the unit.

Teacher Tips

Make the right-angle checker in lesson 1 — students use it all week. Estimation first, measuring second: it stops most protractor errors.

Learning Objectives

• Describe an angle as an amount of turn, and name the arms and the vertex.
• Identify and name acute, right, obtuse and straight angles.
• Estimate the size of an angle using 90° and 180° as benchmarks.
• Measure angles to the nearest degree with a protractor.
• Find a missing angle when angles join to make a right angle (90°) or a straight angle (180°).

Differentiation

Support: Use the paper right-angle checker for every question before naming the angle. Challenge: Introduce reflex angles (more than 180°) and measure them as 360° minus the small angle. English language learners: Pair words with gestures: arms open small (acute), arms in an L (right), arms open wide (obtuse), arms in a line (straight).

What's Included

• Angle picture cards: 8 cards
• Word cards: 8 cards
• Answer guide for matching and sorting

Additional Files

• Grade 4 Math Flashcards: Angles — Acute, Right, Obtuse and Measuring (DOCX)

Teacher Reviews