Was Moses 83 years old when he saw the burning bush?

Moses' age when he saw the burning bush is not specifically mentioned in The Bible. However, traditionally it is said that Moses' life can be divided into three sections of forty years. He was forty years old when he fled from Egypt after killing an Egyptian taskmaster. He spent the next forty years in the wilderness working as a shepherd for his father-in-law Jethro, married two women and had two sons. At the end of these forty years Moses sees the burning bush so he would have been eighty years old at the time. He then receives a call from God to lead the Hebrew people out of Egypt and spends the last forty years of his life leading them in the desert. He dies at the age of 120 years and God buries him on the top of of the mountain.