Jojo is absolutely right. They may not pick up on the errors but I would prepare a revised calculation just in case. At least you can explain the mistake and show that you have thought about it etc. Examiners are human too. In fact, post viva, my internal showed me his PhD abstract and admitted that he only noticed the typo on the very first line moments before the viva! All he could do was cross it out!
Good luck, you will be fine. I found many typos in my thesis and just made sure I had noted them in case they were picked up on in the viva and obviously so I could correct them for the final version.