Proof by deduction

What you'll learn

1. 1

   Imagine you have a secret rule: 'If I add 2 to an even number, I always get another even number.' 🧠

2. 2

   Which of these is an even number?

3. 3

   An even number can be written as 2n, where n is any whole number. So adding 2 gives: 2n + 2 = 2(n + 1).

4. 4

   Let's prove: 'The sum of two odd numbers is even.'

5. 5

   Drag the expressions to build the proof: 'If you add 1 to an even number, you get an odd number.'

6. 6

   What is the first step to prove 'The product of two even numbers is even'?

7. 7

   Proof by deduction shows something is always true. What does the '2' in 2n tell you?