Estimate each sum or difference. Round to the tens place. 45.8+129.25+18+5.649
In the text that I use, when they ask you to estimate an answer, they mean to use front-end rounding on each addend, and add those together. Front-end rounding means to round to the first digit, no matter which place it is in. In this case, you get 50+100+20+6=176. and then round to the tens place, or 180. Hope this helps.