Talking Calculator - Undo, Mul

This is a talking calculator. It has UNDO function so it is easy to fix errors.

1. Text-to-speech voice functionYou can prevent mistakes by hearing the voice2. Undo functionEach time you press the back space button, you can go back to the past input.You can also go back to past inputs after the calculation, so we can respond flexibly to typing mistakes.3. Mutilingual - number formatIt corresponds to the difference in the digital format of each country.(example)1,234,567.89 Japan1 234 567,89 Fra…