Scientific calculators can be rolled back because most scientific calculators have a rollback function. The rollback function allows the user to undo the previous operation, so that the previously entered data or operation can be easily modified. Calculator is a machine invented by modern people that can perform numerical operations. Modern electronic calculator is a hand-held electronic machine that can perform mathematical operations. There is an integrated circuit chip, which is weak in function, but more convenient and cheaper. It can be widely used in business transactions and is one of the necessary office supplies. In addition to displaying calculation results, there are overflow instructions, error instructions and so on. The calculator is powered by an AC converter or a battery, which can be charged by an AC converter or a solar converter.