Albert Einstein, one of the most renowned physicists in history, lived from 1879 to 1955. During his lifetime, calculators as we know them today were not widely available. The electronic calculators we use today were developed and became popular in the 1960s and 1970s, well after Einstein's death.
However, Einstein did make use of calculators that were available during his time. In his work, he often relied on mathematical calculations to develop and refine his theories. Before the advent of electronic calculators, mathematicians and scientists used mechanical calculators or performed calculations manually.
Einstein was known for his deep understanding of mathematics, and he was skilled in performing complex calculations in his head. He had a remarkable ability to visualize and manipulate mathematical concepts mentally. While he would have used various tools available during his era to assist with calculations, such as slide rules and mechanical adding machines, it is worth noting that his genius primarily resided in his mathematical insight and conceptual thinking rather than reliance on computational aids.