Teacher Eddie Woo is changing the face of mathematics in Australia, reaching students far beyond his Sydney classroom by posting his lessons online.
The United Nations says a group of 36 Yazidi people is freed, while an Iraqi commander predicts the complete capture of Mosul from Islamic State militants by May.
US President Donald Trump says he does not know whether North Korean leader Kim Jong-un is sane but believes he is a "pretty smart cookie", adding the US cannot allow the leader to develop better missiles.
Famous climber Ueli Steck, known as the "Swiss Machine" for his speed, is killed in a mountaineering accident near Mount Everest in Nepal, ahead of a planned ascent up the 8,850-metre mountain later this month.
A frustrated Daniel Ricciardo retires from the Russian Grand Prix on only the fifth lap, telling his team his right rear brake was "on fire".
There is no more doubt about it — Adelaide is the AFL benchmark for 2017, as the Crows own the league's last perfect record.