The animation showing all of the triangles, one by one, is available above when you are signed in to your Transum subscription account. If you do not yet have an account and you are a teacher or parent you can apply for one here.
A Transum subscription also gives you access to the 'Class Admin' student management system, many more teaching resources and opens up adfree access to the Transum website for you and your pupils.
Topics: Starter  Combinations  Problem Solving  Shape
How did you use this starter? Can you suggest
how teachers could present or develop this resource? Do you have any comments? It is always useful to receive
feedback and helps make this free resource even more useful for Maths teachers anywhere in the world.
Click here to enter your comments.
Previous Day  This starter is for 23 May  Next Day
Sign in to your Transum subscription account to see the answers
There is a printable worksheet to go with this activity.
Other shape counting starters:
How Many Squares 1?
 How Many Squares 2?
How Many Triangles 1?

How Many Triangles 2?  How Many Triangles 3?
How Many Rectangles?
 Rectangles Investigation 
Icosahedron 
Mystic Rose
Your access to the majority of the Transum resources continues to be free but you can help support the continued growth of the website by doing your Amazon shopping using the links on this page. Below is an Amazon link. As an Amazon Associate I earn a small amount from qualifying purchases which helps pay for the upkeep of this website.
Educational Technology on Amazon
Teacher, do your students have access to computers such as tablets, iPads or Laptops? This page was really designed for projection on a whiteboard but if you really want the students to have access to it here is a concise URL for a version of this page without the comments: Transum.org/go/?Start=May23 However it would be better to assign one of the student interactive activities below. 

Here is the URL which will take them to a related student activity.
See the National Curriculum page for links to related online activities and resources.
Transum Shop :: Laptops aid Learning :: School Books :: Tablets :: Educational Toys :: STEM Books