## Dear Family, your Operation Maths guide to 3-D Objects

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Dear Family, listed below are some practical suggestions as to how you might support your children’s understanding of the maths topic of 3-D objects. Also below, are a series of links to digital resources that will help both the children, and you, learn more about 3-D objects. The digital resources are organised according to approximate class level.

#### Practical Suggestions for all Children

**Naming shapes:**3-D is short for three dimensional, i.e objects with length, width and depth/height. In Operation Maths we refer to them as 3-D objects, so as to distinguish them from their flat, 2-D relations. 3-D objects can also be referred to as solid shapes and they include cubes, cuboids, spheres, cones, cylinders, pyramids, etc. Distinguishing between 2-D shapes and 3-D objects can be a bit confusing for both adults and children; for example, the shape of a real ball may be referred to as a circle, since, if a ball is drawn, or shown in a picture, then the flat, 2-D shape of the ball in the image is now a circle! But in reality, it is a 3-D object called a sphere. And a box is not a 2-D shape, it is a 3-D object called a cuboid, but the flat surface of a box is usually the 2-D shape of a rectangle or, sometimes, a square. So, if looking for 3-D objects at home, ask the children to examine and if possible pick up, actual objects, as opposed to flat representations of the shapes in a picture book or magazine.**3-D Shape hunts:**Play games like “I spy, with my little eye, something the shape of a cube, cuboid, sphere” etc. Again, be careful that you affirm with your child that it is the entire object that you are looking at, as opposed to just a surface or a flat face of the object.

**Sweet!**A great place to find 3-D shapes is in treats and their wrappings or containers. Next treat time, look carefully at your Maltesers (spheres), Toblerone box (triangular prism), Smarties container and Lindor chocolates box (both hexagonal prisms), tub of Quality Street (octagonal prism) Starburst/Opal Fruits (cuboid), mini-rolls and hot chocolate powder (both cylinders) and wafer cones (cone, of course!)**Properties:**Each family of 3-D objects also has properties or characteristics that make them different from other 3-D objects. In the younger classes, the children will be exploring whether a 3-D object can roll, stack, slide etc. When out and about or helping around the house, children can be asked to name the 3-D objects that are easier to stack on shelves in the shop, in the cupboard etc? What 3-D objects might roll off a shelf? As the children get older, they will be exploring properties such as the number of corners (also called vertices), the number and type of edges (straight or curved), and the number and type of surfaces (flat faces or curved surfaces). Through developing a better understanding of what makes an object that 3-D object, the children can start to group 3-D objects with similar properties or characteristics together.**Take it apart!**3-D objects and 2-D shapes, as mentioned earlier, are very connected. Another way that children can explore this relationship is to take apart examples of 3-D objects. Boxes are ideal for this, so, before you put your boxes in the recycling bin, ask your child to tear it open along an edge so as to open it out flat and identify the 2-D shapes that make it. This is referred to as the 2-D net of a 3-D object. Did they see the 2-D shapes they expected to see?**Play, play, play!**Encourage your child to play and explore with 3-D objects as much as possible:- Lots of the toys that are aimed at preschool age children focus on 3-D shapes: wooden building blocks, shape sorter toys etc. Even older children can return to these toys and look at them in a new way to see what they can now discover and say about these shapes.
- Magformers , Geomag and 3-D puzzles are examples of toys specifically geared towards the construction of 3-D structures. Other toys that can be used to create 3-D structures include Lego, K’nex, Mega Bloks, Plus-Plus and Stickle Bricks/Bristle Blocks.
- Build anything! Use boxes and any objects from around the home to build, stack, etc. Without even realising it, the children will be exploring and learning about the properties of these shapes.
- Solve 3-D puzzles. Perhaps you have a Rubik’s Cube somewhere around the house? Or look out for other 3-D puzzles like Rubik’s Cage, Soma cube or Tetris Shake. Any of these these type of puzzles are a very worthwhile way to spend time!

#### Digital Resources for Infants

The Number Jacks have quite a number of 3-D shape-based episodes including Sphere today, Gone tomorrow, a Circle at both ends (cylinder) and Boxing Day.

3-D Shapes Song: Introduces cone, cylinder, cube and sphere.

3-D Solids: A video lesson from Matholia introducing common solid (3D) shapes, including cubes, cuboids, cones, cylinders, spheres and pyramids.

I know it – Geometry & Shapes Try the solid shapes interactive quizzes for Kindergarten

Solid Shapes: A selection of games from ixl.com. You can do a number of free quizzes each day without having a subscription. Activity L1-L7 are all about solid, 3-D objects.

Math Games: a whole suit of geometry games, for all class levels; choose the skill you want to practice.

#### Digital Resources for First and Second Classes

*NB: Children in first and second may also enjoy the links for infant classes, above*

Describing and Naming Solids: A video lesson from Matholia describing the properties of common solid (3D) shapes, including cube, cuboid, cylinder, cone and sphere.

White Rose Geometry: a series of lessons on 2-D and 3-D shapes. These lessons could be followed up with other geometry lessons in year 2

What Shape am I? Use the clues to identify the name of the 3-D object. Guess the name before you click on to see the answer.

Drawing 3-D Objects: Video to show how to draw 3-D objects. Drawing is a great way to understand these shapes better.

I know it – Geometry & Shapes Scroll down to the interactive quizzes for Grade 1 and for Grade 2

3-D Shapes: A selection of games from ixl.com. You can do a number of free quizzes each day without having a subscription. Activity N1-N10 are all about 3-D shapes.

Math Games: a whole suit of geometry games, for all class levels; choose the skill you want to practice.

#### Digital Resources for Third to Sixth Classes

*NB: Children in these classes may also enjoy the links for first and second classes, above*

Maths is Fun: Background information on 3-D solids as a part of geometry.

Describing and Naming Solids: A video lesson from Matholia describing the the characteristics (e.g. faces, edges, corners) of common solid (3D) shapes, including cube, cuboid, cylinder, cone and sphere.

Khan Academy – Solid Shapes: Watch this series of videos on geometric solids and answer the practice questions.

3-D Shapes: Lots of useful information about 3-D shapes from BBC Skillswise, including a video highlighting 3-D shapes in the real world.

Drawing 3-D Objects: Video to show how to draw 3-D objects. Drawing is a great way to understand these shapes better.

Cube Nets: Can you predict which of these nets will form a cube? Make your prediction and then watch the animation to see if you were correct.

IXL: A selection of geometry games from ixl.com. You can do a number of free quizzes each day without having a subscription.

I know it – Solid Shapes: Interactive quiz for Grade 3 and another one for Grade 4

Kangaroo Hop: Get your kangaroo to the finish line first by choosing the correct 2-D or 3-D shapes.

Math Games: a whole suit of geometry games, for all class levels; choose the skill you want to practice.

3-D shape quiz: For 5th or 6th class or those looking for a challenge!