Everyday Mathematics
Why a triangle’s angles add to 180 degrees on a flat surface
Use a paper triangle to explore the 180-degree angle sum, then connect the observation to a parallel-line argument that explains why it works.
LEARN · QUESTION · DISCOVER
classroom activities
Learning Mathematics
A shape can have rotational symmetry without mirror symmetry
Use paper shapes to distinguish turning symmetry from mirror symmetry and explain why one test does not replace the other.
Learning Mathematics
Why pi stays the same when a circle gets bigger
Compare circular lids to see why circumference divided by diameter approaches the same number. A practical activity separates pi from measurement error.
Learning Mathematics
Show why a fraction’s denominator does not add when the parts match
Use equal paper strips to explain addition with matching denominators, showing that the number of pieces changes while the size of each piece stays the same.
Learning Mathematics
An Independent Event Does Not Remember the Previous Coin Toss
A run of heads does not make tails due on the next independent toss. Use a small classroom example to separate a sequence from the next event.
Learning Mathematics
A Square Is a Rectangle With an Extra Condition
Help children classify squares and rectangles by their properties, using paper shapes, right angles and a simple sorting activity.
Learning Mathematics
Changing Units Does Not Change the Length
Use a measured ribbon and a simple conversion example to show why changing from metres to centimetres changes the number, not the object.
Learning Mathematics
An Equals Sign Describes a Balance, Not an Instruction to Calculate
Use counters and varied number sentences to help a learner see the equals sign as a relationship between two values.
Learning Mathematics
Zero Belongs With the Even Numbers: Show It With Pairs
Zero is even because it can be divided into two equal whole-number groups with none left over. Use pairs to make the idea visible to a learner.