Go Math! Grade 1, Chapter 11: Three-Dimensional Geometry
In this unit, first graders explore three-dimensional, or solid, shapes like cubes, cones, cylinders, spheres, and rectangular prisms. They sort them by attributes, such as flat surfaces and whether they roll, and combine solids to build new shapes. After graphing data in the last unit, this begins the year's geometry, and next they turn to flat, two-dimensional shapes.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Chapter 11?
- Sorting solid shapes by attributes like flat surfaces, curved surfaces, and whether they roll, stack, or slide. Learn more: What makes a triangle a triangle
- Putting solid shapes together, like a cone on a cylinder, to build new shapes and naming the pieces used. Learn more: Building bigger shapes from smaller ones
Sample questions to try together
These are real questions from our practice. Tap the speaker to hear one read aloud, or the light bulb for a hint, and talk about the answer together.
Question 1 of 3
What must be true for a shape to be a triangle?
- It must have 3 straight sides.
- It must be blue.
- It must be big.
How you can help
- Gather a can, a box, a ball, and a party hat or funnel, and ask which ones roll, which stack, and which do both. Name each solid shape as you go.
- Build a tower or a castle from boxes and cans together, and ask your child to name the shapes they used and which ones work best at the bottom.
- Go on a solid-shape hunt on a walk or in the kitchen, looking for a cylinder, a cube, and a sphere.
Where kids can get stuck
- Calling a cube a square, mixing up a solid shape with one of its flat faces.
- Calling a cylinder a circle because its flat ends are circles.
- Deciding a cone lying on its side is no longer a cone.
Practice makes perfect
Bobby's Math Club has practice problems that adapt to your child’s level, each with a detailed explanation and an easy-to-follow video, so your child can build confidence in these skills one step at a time.
Words your child will hear
- three-dimensional
- Solid, like a box or a ball, which you can hold.
- attribute
- A feature of a shape, like how many sides or corners it has.
- cube
- A solid shape with 6 square faces, like a block.
- cone
- A solid shape with a circle at one end and a point at the other.
- cylinder
- A solid shape with two circle ends, like a can.
- sphere
- A solid shape that is perfectly round, like a ball.
- rectangular prism
- A solid shape with 6 rectangle faces, like a box.
- flat surface
- A flat side of a solid shape, also called a face.
- curved surface
- A rounded part of a solid shape that lets it roll.
Want to help your child master solid shapes?
In Bobby's Math Club, your child practices these skills at just the right level, with a hint when they need one, a clear explanation after every question, and kid-friendly videos. Unlimited practice is free.
Join the club
Written by Robert “Bobby” Barnett
Bobby is an award-winning math teacher, the author of Meet Every Learner’s Needs, and the father of two elementary-school math learners. He uses Bobby’s Math Club with his own kids a few times every week. Learn more or contact Bobby.
Which math standards does Go Math! Grade 1 Chapter 11 cover?
Go Math! Grade 1 Chapter 11 covers these math standards. Each one links to what it means, sample questions, and teaching strategies.
For teachers: Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence. Learn how Bobby's Math Club can help your students grow.