In mathematics, many students in higher grades are like old computers that you want to use on the Internet: They still work, but they are too slow. They simply can’t keep up. The reason is often quite banal: Many students can’t do mental arithmetic properly.
Even if it’s not as obvious after elementary school, math is always done in the head. Whether it’s reducing fractions, dissolving parentheses or converting units: The multiplication table is omnipresent. Those who then need some time or even the calculator for simple calculations end up lacking the capacity for the actual task.
Therefore, from the first grade on, but also in secondary school, use every opportunity to train mental arithmetic! Of course, this also means not using the calculator on your smartphone for homework!
Tip: You can practice mental arithmetic quickly – but you can also unlearn it. Therefore, it is worthwhile to solve halfway simple calculations in your head even if you are actually allowed to use a calculator. Because such calculations also occur in other subjects and in situations in which electronic calculation is not possible or permitted.