Grade 4 Math Book of the Week · October 19, 2026
Sir Cumference and the First Round Table
by Cindy Neuschwander
geometry More grade 4 books
King Arthur's knights can't hear each other around their long rectangular table. Sir Cumference, his wife Lady Di of Ameter and their son Radius try one shape after another (square, diamond, octagon, oval) until they find the perfect fit.
Why it's useful
Wordplay and a quest make this a memorable way to talk about properties of 2D shapes and the vocabulary of circles.
- Why shape matters. Each table fails for a reason (too long, sharp corners, too wide), so kids reason about sides, angles and corners.
- Circle vocabulary sticks. Circumference, diameter and radius are hidden in the names, and kids remember them.
- Classifying shapes. Rectangle, square, parallelogram and octagon make a natural lead-in to sorting shapes by their properties.
Try it in class or at home
- Table design challenge. Groups cut paper tables in each shape and decide which seats the most knights who can all see each other.
- Name game. Kids label a circle with the character names: Sir Cumference, Lady Di of Ameter, Radius.
- Shape sort. Sort the story's tables by number of sides, right angles and parallel sides.
- String circles. Use string and a pencil to draw a circle and measure the radius and diameter.