It means you need to dust off your 'big number' maths skills to work out what something costs. The fat wedge of cash you see me handing over at the top of the page is seven and a half million Ugandan Shillings. Are you up for some mental maths? Seven and a half million divided by five thousand?
Any of you with the mental agility to come up with £1500 is better at this kind of thing than I am.
Carol and I are both in total agreement about this particular £1500 - it is by far and away the most pleasing money we have ever spent. The precise nature of the transaction which we had just shaken on in the picture was seven and a half million Ugandan shillings for 3000 packs of Always Maxi Thick sanitary towels. This we are assured is enough to meet the needs of every one of the 250 female pupils at the Kamuganguzi Janan Lewan Memorial (KJLM) Secondary School for the next year.
What numbers can describe the impact of this? Well lack of sanitary ware means the girls are missing an average of 50 school days per year. And they do long school days out here. Lessons start at eight and end at five with an hour off in the middle of the day for 'Posho' and beans. You only have to take the briefest of glances into one of the classrooms to see how every word of the teacher is hungrily absorbed. Families have to make vast sacrifices to pay for their children to receive secondary education and the children know it. Every minute is made to count.
If one person can achieve the grades to secure a well paid regular job, then they are then able to look after an extended family of up to thirty.
So. Fifty extra days of class time a year? Four hundred extra hours of class time per year? That equates to a jaw dropping 100,000 extra hours for the 250 girls at Kamuganguzi Janan Lewan Memorial (KJLM) Secondary School.
Maybe these extra hours might tip the scales for twenty of the girls. Maybe these extra hours will be the key to better 'O' and 'A' level results and twenty good jobs which otherwise might not have been reachable.
And at this point the maths become even more eye watering. I will assume each of the girls has an extended family of 25. So an extra 500 people are provided for. Secondary school fees are covered for many more children of the generations to come.
And so on it goes. This is how the so called developing world can roll. The ripples caused by a fairly small pebble in the pond can run and run.
Yesterday Penina, the school's deputy head, told us about the gut churning sadness she feels every time a talented pupil is forced to drop out. She told us how they would often as not 'go to the stones'.
'The stones' are the place underneath the bottom rung of the ladder. You go to the stones when there is nowhere else to go. When an unusually ferocious storm lashes the hillsides hard enough, the structure of the earth is disturbed and a landslide moves a few hundred tonnes of soil and rock. This leaves the underlying rocks open and exposed and a new quarry is born.
Family groups make their way to the opened earth to break the stone down into different sizes with hammers. The oldest worker on the site might be a grandmother in her seventies. The youngest workers are under five. The rate of pay is measured in plastic washing up bowls.
So you take a basketball sized stone and smash away at it until you have enough gravel to fill up a plasic washing up bowl. How long does such a task take? I have no idea. It would take me ages and my hands would be a mess of blisters by the time my bowl was ready for inspection.
A full bowl of freshly smashed gravel weighs in at 200 Ugandan Shillings. This can sound like a tidy sum when you think in terms of Oliver Twist or taking the 'Queen's Shilling'. In reality it doesn't get you much.
If you buy a hard boiled egg from a ten year old trainee entrepreneur on the streets of Kabale Town, it will set you back five hundred shillings. So to earn enough to buy a single hard boiled egg you need to smash up enough stone to fill two and a half washing up bowls with gravel. Three and a half bowls gives you enough to pick up a roasted corn cob.
A room for the night of the most basic type? 25 washing up bowls worth.
Forty hours a week of work at our new minimum wage in Scotland would be enough to trade in for 1.7 million Ugandan Shillings. A lot, right? Sure it's a lot. More to the point, it is 8500 plastic washing up bowls worth of smashed up gravel.
Realistically, how many bowls could I fill in a week if the skin on my hands actually allowed me to wield a hammer for forty hours? Twenty? Twenty Five? I have no idea. Enough for ten hard boiled eggs? Eight roasted cobs of corn? No wonder it breaks Penina's heart when a talented pupil drops our of class to 'go to the stones'.
OK. Time for som even bigger maths. Huge, ginormous maths. When we get back home it will be time to get the show on the road and to try and raise some funds to provide enough sanitary ware for another three schools. I plan to drop a line to Liverpool's new star African striker, Sadio Mane. Sadio hails from Senegal and I guess he will be all too familiar with how life is for those who have no other choice than to 'go to the stones'. Maybe he might have had to go to the stones himself had he not been born with such a God given talent.
I guess Sadio will be earning somewhere in the region of £150,000 a week. So here goes. That is seven hundred and fifty million Ugandan Shillings. And that is three million and a three quarter million washing up bowls of smashed up stone. Wait for it. If you were line up this many washing up bowls filled with smashed up stone, the line would be eight hundred and fifty miles long. At my optimistic rate of filling 25 bowls a week, it would take me four hundred and thirty years to earn what Sadio nails down for kicking a ball around for seven days in Liverpool.
Like the song says, it's a mixed up, muddled up, shook up world.
My pitch to Sadio will have nothing to do with washing up bowls filled with smashed up stone. Instead I will point out the alarming fact that most of the lads out here are wearing Arsenal shirts and something needs to be done to get more them of them wearing Liver Bird crested red. If he was sort out a year's worth of Always for a couple of schools, well who knows, in a year's time the streets out here will have more of an Anfield feel to them. Sure, it's a long shot but anyone involved in any kind of charity will tell you all about the 'if you don't ask, you don't get' thing.
A couple of days ago, new research revealed the wholy unsurprising fact that the richest 1% of humanity now owns more than the poorest 50% put together.
That is a set of figures on a piece of paper. When you drive past the ones who have 'gone to the stones', the numbers jump off the page and form into an unmerciless reality.
And our seven and a half million Ugandan Shillings? Fair enough, it is nothing more than a drop in the ocean but we couldn't be any happier about it.
3000 packets of Always Maxi Thick arrive at their destination.