One could be forgiven for thinking Celtic are going back to school this week.

There's more than a touch of the three Rs about their next three encounters. For reading, writing and arithmetic read Ross County, Rangers and Real Madrid.

The Hoops will take on all three opponents from Wednesday onwards both domestically and in Europe.

Celtic boss Ange Postecoglou was only interested in a fourth 'R' when the Hoops visited Tannadice yesterday: repetition.

The Aussie duly got his wish. Celtic swashbuckled their way into Tannadice and rode away with all three points to make it five Scottish Premiership wins out of five with an emphatic 9-0 over Jack Ross's beleaguered Dundee United.

In terms of reading, it was another fabulous chapter in Celtic's domestic repertoire.

In terms of writing, it was the same old story with the same old Celtic, always winning.

In terms of arithmetic, it was all about five league wins from five, 15 points from 15, the 100 per cent record intact, 21 goals scored with just one conceded and a two-point lead at the top of the Scottish Premiership.

For the statisticians out there in terms of the unbeaten league run, it's 37 and rising. The Aussie's men have certainly got the hang of this domestic malarkey.

Rampant and ruthless, Celtic simply never stopped.

A quite superb first half-hat-trick from Kyogo Furuhashi which took his tally to six for the season and a strike from Jota had the Hoops on easy street as they peeled open the Tangerines at will.

A second-half treble from winger Liel Abada and goals from Josip Juranovic and Carl Starfelt had the Celts on cloud nine. A David Turnbull header bounced the wrong side of the line to prevent them from scoring the perfect 10.

Here's another 'R', Postecoglou can conjure: record-equalling.

Celtic's margin of victory at Tannadice matched the club's highest-ever score from the Scottish Premier League era (they beat Aberdeen 9-0 in 2010).

It is also the highest-ever away win in the modern SPFL Premiership era by any side. That's no mean feat.

Celtic inflicted a bruising defeat on the Taysiders and it is small wonder that Tangerines boss Jack Ross branded it humiliating and embarrassing.

READ MORE: Detailed Celtic player ratings as Kyogo Furuhashi and Liel Abada bag hat-tricks in 9-0 Dundee United demolition

It's just a measure of what Postecoglou's Celtic side can do to teams.

Ross needn't worry though as the Taysiders won't be the last team to fall under their irresistible spell this season if they are in that kind of mood.

Postecoglou is slowly but surely turning Celtic into a slick and well-oiled machine. Domestically under the Aussie, it appears to be stuck on the one cycle win, rinse, repeat.

And whisper it quietly but how long before the comparisons are being made with Brendan Rodgers's Invincibles squad?

It was Postecoglou who recently said himself that the kind of football that he's constantly striving for his teams to play may well not even exist.

But the Hoops must have come mightily close to his vision of football utopia on Tayside.

The fans would certainly argue that case. I've referenced this tune before but there's a party atmosphere in the stands whenever the supporters watch their team play these days.

There was even a rousing rendition of the 1957 League Cup final song on show at Tannadice. Piling on the agony, putting on the style.

The visitors administered nine lashes of the 'Leather Belts' against United. It was a joy to watch at times.

Speaking of school, the Tangerines were handed a harsh and painful lesson. Celtic essentially meted out a tutorial in ruthlessness and a masterclass in being clinical.

It was also an education for the rest of Scottish football.

Celtic piled on the agony for Ross but they put on the style for Postecoglou.

A week on Tuesday it will be the manager's first crack at European football's premier club competition as a boss. He's waited nearly two decades to become an overnight coaching sensation.

When the Champions League ball bounces for 'Real' next Tuesday inside Paradise we shall see exactly if Postecoglou and his charges are made of the right stuff at the highest level.

So far under the Aussie the Hoops have proven to be quick learners. It's certainly not fantasy football and it most certainly does exist. It's also called winning football.

If Celtic can replicate anything like their Tannadice performance on the European stage then they could make Champions League history in the present.

Piling on the agony and putting on the style at the Champions League level? Why the very thought would make everybody connected with Glasgow Celtic smile from ear to ear, wouldn't it?