I would split 64 into 60 & 4, and 43 into 40 & 3
Than i would add the 60 and 40 together (which will give me 100)
I will than add 4 & 3 together (which will give me 7)
Than i will add 100 and 7 together, which will give me 107
107 is your final answer
hope this helps
