ELEMENTORUM vs Mental Math Interview Trainer

Learn the elements of the periodic table in a playful way. All chemical elements have a natural position in the periodic table, which are queried in a quiz-like manner in this ELEMENTORUM app. The tasks are designed so that you benefit from learning how professional chemists memorize the arrangement of the elements. And here's a secret: Very few chemists know ALL chemical elements and their positions in the periodic table by heart. However, what every chemist knows exactly are the main group elements such as H, O, N, C etc. Of the 9 levels in this app, the first 4 levels focus solely on the main group elements. Only then do the subgroup elements such as Co, Ni, Fe, etc. come. In ELEMENTORUM, the subgroup elements are added to the quiz questions in levels 5 to 7. And only the very diligent ones learn the lanthanides and actinoids by heart. But take on the challenge in levels 8 and 9 and try to solve all the tasks correctly. And here's another secret: No chemist learns the periodic table line by line, or row by row, or period by period. Chemists learn the periodic table from top to bottom, column by column, or group by group. And why? Because elements in the same column or group have the same or similar chemical properties. For example, the alkali metals Li, Na, K, Rb and Cs. Or the halogens F, Cl, Br and I. Or the noble gases He, Ne, Ar, Kr and Xe. So it simply makes more sense for a chemist's work to memorize the elements in groups than in periods. In the ELEMENTORUM app you are shown a section of the periodic table in each task, i.e. 3-4 rows (periods) and 3-4 columns (groups). The position of one element should be found. Orientate yourself on which elements are to the left and right of the element you are looking for, but focus in particular on the elements that are above and below. Then, with a little practice, you will be able to assign more and more elements to the correct positions and become a master of the periodic table.

Mental Math helps you build fast, reliable mental calculation skills through short, focused practice sessions. Whether you are preparing for consulting interviews (McKinsey, BCG, Bain), finance or tech case interviews, or any role that tests quantitative reasoning, this app gives you a simple way to drill the exact skills you need: quick multiplication, percentages, division, and growth calculations. Practice in three modes: • Speed: solve as many problems as you can before the clock runs out • Accuracy: answer a fixed set of questions and aim for precision • Custom: pick specific categories and set your own time limit Adjust difficulty from Easy to Hard and fine-tune the tolerance margin so drills match your current level. Your results are saved locally on your device so you can track progress across sessions and spot improvement over time. Features: • Short daily mental math drills designed for interview prep • Speed, Accuracy, and Custom practice modes • Multiplication, percentage, division, and growth exercises • Adjustable difficulty and tolerance controls • Session summaries and long-term performance stats • Lightweight, distraction-free design • Available in English, French, and Spanish Perfect for consulting interview prep, case interview math, finance interviews, product management interviews, or anyone looking to sharpen their everyday arithmetic.