While estimating you would round the decimals and you would think in terms of how would the answer look like when you multiply 64 with 10... 640ish..and then you think about the decimals a little,,, soyou will put decimal after 64... and that will give you 64.0 or something ...While the exact answer id 65.79... Close enough.
Hope I helped..
Please mark the brainliest if I did help!
