Bridges in Mathematics Grade 1, Unit 5: Geometry
In this unit, first graders look closely at shapes and the attributes, or features, that make each one what it is, like a triangle's three straight sides. They build bigger shapes from smaller ones and cut shapes into halves and fourths. It extends the equal shares from the last unit, and next they return to number, practicing addition and subtraction facts to 20.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Unit 5?
- Naming shapes by their sides and corners, and knowing that color, size, and which way a shape is turned don't change it. Learn more: What makes a triangle a triangle
- Putting flat shapes together, like two triangles into a square, and stacking solid shapes, like cubes and cylinders, to make new ones. Learn more: Building bigger shapes from smaller ones
- Splitting circles and rectangles into halves and fourths and seeing that more equal shares means each share is smaller. Learn more: Halves and quarters of circles and rectangles
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
- Hunt for shapes on a walk or around the kitchen, and ask your child to prove each one by counting its sides and corners. Turn a plate or a box to show it's still the same shape.
- Cut paper squares in half from corner to corner, then ask your child to put the two triangles back together in new ways and name the shape they made.
- Share a pancake or tortilla by folding it into halves, then fourths. Ask which piece is bigger, a half or a fourth, and why.
Where kids can get stuck
- Deciding an upside-down triangle isn't a triangle anymore because it doesn't look like the usual picture.
- Calling a square turned on its corner a diamond, and so not a square.
- Thinking a fourth is bigger than a half because four is bigger than two.
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
- attribute
- A feature of a shape, like how many sides or corners it has.
- side
- A straight line that makes part of a shape's edge.
- vertex
- A corner, where two sides of a shape meet.
- closed shape
- A shape with no gaps or openings in its edge.
- trapezoid
- A four-sided shape with one pair of sides that run the same way.
- cube
- A solid shape with 6 square faces, like a block.
- cylinder
- A solid shape with two circle ends, like a can.
- half
- One of two equal parts of a whole.
- fourth
- One of four equal parts of a whole, also called a quarter.
Ready to build your child’s confidence with shapes and equal parts?
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 Bridges in Mathematics Grade 1 Unit 5 cover?
Bridges in Mathematics Grade 1 Unit 5 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.