Have you ever suspected that Asian kids are maths wizards, or that the Scandinavians seem to have it figured out, too? Well, wonder no more. 

New rankings have just been released that compare 76 countries in terms of how good their 15 year olds are at maths and science, and it makes for some interesting reading. The rankings were done by the OECD think tank, and have Singapore coming out on top, followed by Hong Kong and South Korea.

Bringing up the rear of the 76 countries is Ghana, followed by South Africa. But while these school rankings are the world's most thorough attempt to rank nations, I need to point out that there are over 190 countries in the world, and only 76 in this list. The countries in the OECD's rankings are mainly the better organised ones, where reliable data is available. It's certain that Ghana and South Africa wouldn't be at the very bottom if it was possible to include every country on earth.

Here are the top 15!

Personally, I wasn't too surprised by a few of these. I always expect Finland, Switzerland, Germany etc to be up near the top. Singapore has been doing very well at this sort of thing for a couple of decades now, but it's worth remembering that in the 1960s, the place had now literacy and a shortage of drinking water. It's proof that it's possible to climb this ladder, all the way to the top.

Poland and Vietnam are also doing really well. Both of these countries were really struggling 25 years ago - Poland was in the midst of the collapse of the USSR, and Vietnam was recovering from a very destructive war. The fact that their 15 year olds are performing so well at school suggests that the economic future of these two countries is going to be bright.

Who didn't make the top 15? The USA is down at number 28, suggesting that while the nation is home to many of the world's best education institutions, there are a lot of kids who are missing out and dragging the average down. The UK came in at number 20, with France at 23, and Italy equal with the USA at 28. Brazil and Indonesia, two of the most populated countries in the world, ranked at 60 and 69 respectively, indicating that there's a lot more work to be done to prepare the next generation. Big countries like China, India, and Nigeria weren't included in the ranking, and I hope that there's enough reliable data to include them the next time that this sort of ranking is done by the OECD.

But what if all 15 year olds received a basic level of education?

A classroom in Ghana

Luckily the rankings report answers this question, too. For each of the 76 countries, the OECD estimated how much bigger their economies could be if every 15 year old kid reached a basic education level, and the numbers are really surprising. Ghana, which came 76th in the rankings, could theoretically get a 3881% boost to its economy if its kids received a good education. Even the USA has a growth potential of 153%, the UK 143%, Australia 130%, and Germany 108%. These are really big numbers!

The bottom line

It's no secret that countries that invest in education have a better chance of lifting their people out of poverty, and that international aid spending that addresses basic education has a big impact. Organisations like the Global Partnership for Education have the goal of ensuring that every child receives a primary school education, no matter where they are. Fantastic progress is being made towards this goal, but around 59 million kids are still missing out. Primary school education is the start of the journey - we're not going to get a nation full of 15 year olds with good maths and science skills unless we get them through primary school a few years earlier.

It's significant that these rankings have been released in the first half of 2015, because in the second half of 2015, the world's leaders will meet at the UN to decide on a set of global development goals (called the Sustainable Development Goals, or SDGs) that will cover the 2015-2030 period. With education being such an important tool to overcome poverty, it's vital that the SDGs contain an ambitious target for global education.