This painting is called The Measurers. It is painted on wood and was done in Flanders about 450 years ago.
In The Measurers lots of everyday activities which use maths have been painted. In the front of the painting on the right a woman is using a ruler to measure cloth. In the middle a craftsman is using a compass to draw a circle on a piece of wood. On the left a music teacher is teaching a pupil about the maths of lengths of notes in music. In the background on the left two men are using a balance to weigh sacks. In the middle another two men are using a gauging rod to measure the volume of beer left in a barrel. On the right two surveyors are using mathematical instruments to measure the height of a building. The painting is making the point that you need to understand maths well in order to do all these things.
In the front of the painting many mathematical instruments and objects are laid out on the floor. On the left is a globe of the earth with lines of latitude and longitude drawn on it. In the middle are a pair of dividers, a mason's level for making sure walls are horizontal, a quadrant (either for doing calculations or for telling the time), a ruler, a set square, a gauging rod, and a pair of scales. The funny-shaped object just to the right of the middle is a polyhedral sundial. This is used to tell the time in many different ways. It is shown in the painting because in the 16th century sundials were the most complicated everyday objects that needed mathematical principles to work properly.
The Measurers is a very famous painting for maths historians. This is because old paintings showing mathematics being used to do practical things are very unusual. Most old paintings with mathematical themes are to do with maths theory. They show maths being done as a scholarly activity in universities by professors. Others are about the mystical aspects of maths - things like magic squares, triangular numbers, Platonic solids and mystical pentagrams. In contrast, The Measurers is all about maths being used to solve everyday, manual, down-to-earth problems.
The Measurers was painted in Flanders, which is now a region in Belgium. The towns of Antwerp, Louvain, Brugge and Brussels are all in Flanders. All of these towns were very important places where trade was done in the Renaissance - buying and selling cloth, grain and other goods, for example. They were also very important centres for mathematics because maths is so important for trading: goods must always be carefully measured, weighed and counted, not to mention money.