Show Mirror Image

Show Mirror Image

Show Mirror Image

Show Mirror Image

Show Mirror Image

Show Mirror Image

Show Mirror Image

Show Mirror Image

The bottom half of some symmetrical calculations are shown above.

Can you work out the answers?

Can you make up some other calculations where the calculation and the answer both have horizontal lines of symmetry?

Can you make up some other calculations that have vertical lines of symmetry?

## A Mathematics Lesson Starter Of The Day

• Aimee Hamilton, Harrytown Catholic High School
•
• 80+101=181
• Abigail Latham, Swinton
•
• Hello.
Im Abigail Latham From St. Charles Rc Primary School Swinton Manchester
And I Found That 300+100+300+300=1000
30+30+30+10=100
10x10=100
• Abz :D, St Charles Rc Primary
•
• -100+300+300+300=800
800x10=8000
0x10=0
300.08x10=3000.8
=]:D
• Alice K, St Matts
•
• 100 + 88 +111 +1 = 300.
• Primary 7, Bargeddie Primary School
•
• We enjoyed this starter, especially since one of our groups are studying symmetry...
Here are some of our examples:
333 - 333 + 1 = 1
33 x 3 + 1 = 100
11 x 3 = 33
111 - 111 + 8 = 8
Callum in our class also noticed that multiplying any combination of multiples of 10 would give a symmetrical answer:
e.g. 1000 x 1000, 1 000 000 000 x 1000, 10 x 100 000 000 000 etc.
• Mr. T, Gartree High School
•
• Good for younger groups like year 7s since the sums are pretty straight forward but they liked trying to work out how to reflect the digits.
• Prendergast, 9.1 Maths
•
• 11 + 11 + 11 = 33
11 + 11 + 38 + 10 + 10 = 80
8 x 1 = 8
11 x 3 = 33
11 x 8 = 88
13 + 18 = 31
3 x 1 = 3
1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 = 8
1 + 1 + 1 = 3
symmetrical number x 0 = 0.
• Tomiloba Awosika, Bishop Challoner School
•
• Tomiloba from Bishop Challoner School 8B3 has come up with an example - 300 + 300 + 300 - 100 = 800.
• Elliot, 7X3WO
•
• 10+0=10.
• Octavia Pullman, London School Of Rock, London
•
• 30+8= 38.

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.

Previous Day | This starter is for 10 March | Next Day

 l l + 38 = 49 88 x 33 = 2904 838 - 383 = 455 l 8 l x l l = 1991 3 l + 3 l + 3 l = 93 l 0 x l 0 l + l l l = 1121 l 8 l x l 3 l - 80 = 23631 l 380 + 38 - 83 = 1335

Your next challenge is to make an equation with a horizontal and a vertical line of symmetry or a mathematical ambigram

A Mathematical Ambigram is an expression or equation which can be read and has the same or a different meaning when rotated through 180 degrees. A simple example is:

88 + l l = l l + 88

Ambigrams were made famous in Dan Brown's novel "Angels and Demons"

Image From Wikimedia Commons created by Basile Morin. Creative Commons Attribution-Share Alike 4.0 International license.

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

Here is the URL which will take them to an activity about rotational symmetry.

Transum.org/go/?Num=277

The Non-Statutory Guidance (for the English National Curriculum) states that before beginning transforming shapes at Key Stage 3, students should already have a
secure understanding of the following learning outcomes from study at upper Key Stage 2:

• Identify, describe and represent the position of a shape following a reflection using the appropriate language, and know that the shape has not changed.
• Reflection in lines which are neither horizontal nor vertical presents increased challenge and requires students to have a sense of where the image will be.

Key ideas

• Understand the nature of reflections and appreciate what changes and what is  invariant
• Understand the minimum information required to describe a reflection (line of reflection)
• Reflect objects using a range of lines of reflection (including non-vertical and non-horizontal)

Transum has a Starter which provides practice reflecting shapes on squared paper. It is called Reflective Cat.

For Students:

For All: