Covers the principle of counterexamples as well as proofs to do with even/oddness, consecutive numbers and digits. For high ability students.

## Mr Mathew Smith

### 2nd Apr 2018 Flag Comment

I am very impressed with the standard of work. Keep up the good work and see you tomorrow

## Mrs. Marian Olonade-Taiwo

### 17th Nov 2017 Flag Comment

One of the teachers where i am offerred classroom experience referred me to your site because I will find it beneficial and very useful for its resources, high standard of wealth of knowledge, examples etc.

## JamezH21

### 14th Apr 2017 Flag Comment

5 d) is false because IF BOTH a and b are smaller than -1 (negative), then ab>1 (for example -2 times -3=6 which is bigger than 1. So the docx is right

## prisha

### 22nd Feb 2017 Flag Comment

how can 5 d) in the counterexamples.docx be false.maybe the question is wrong

## A Carpenter

## 22nd Apr 2020 Flag Comment

Very useful, thank you