Learning American English idioms is important for learning to speak English fluently. I wrote a book of the 250 most common idioms that are used in business English. These are idioms I have heard frequently while working in American companies during the last 30 years.
If you can learn one new idiom a day, your English speaking skills will be much higher.
Today’s idiom is:
A rough calculation.
My back-of-the-envelope calculation is that this product will be at breakeven within a year.
Back-of-the-envelope describes when a person grabs any available piece of paper (such as an envelope or piece of scrap paper) to make a quick calculation with a pen or pencil. Since the calculation is done in haste and without a calculator or spreadsheet, the implication is that the calculation is rough, not 100% accurate.
The book is on sale from July 6 to July 10, 2017 on Amazon and the link is here: https://goo.gl/wt6ECX
All my English as a Second Language books are published on Amazon and the book series can be found on my Amazon Author Page at https://goo.gl/DyFjck