1. measurement: measurement is essential in making furniture and buildings. This includes length, angle, area, etc. Therefore, basic mathematical knowledge can help you to measure and calculate better.

2. Geometry: For many woodworking projects, geometry knowledge is necessary, such as how to calculate and draw angles, arcs and curves.

3. Proportion and scale: Proportion and scale are also important when making furniture or buildings. You need to know how to calculate the scale and size according to the actual size, and how to draw the scale and scale map.

4. Cost calculation: For carpenters, it is necessary not only to make exquisite and high-quality furniture and buildings, but also to control costs economically and reasonably. This requires a certain grasp of numbers and calculations.

Therefore, although the mathematical foundation is not good, it is not too difficult to learn carpentry as long as you master basic arithmetic and geometry and understand the calculation method of proportion and scale. Besides, you can also teach yourself or take some training courses to improve your ability.