Here is the list of mathematical exercises on mental calculation available online for free. Each corrected exercise is accompanied by indications, reminders of the course, and methodological advice, which allows you to practice independently.
N°1110 (mental math games) : Countdown is an arithmetic exercise that allows you to practice quick mental calculation in an efficient way. The goal is to reconstruct an integer using other integers and basic arithmetic operations (+,-,*,/).
Exercise example :
Use yellow numbers and blue arithmetic operators to calculate the target number.