Seema used compatible numbers to estimate the product of (–25.31)(9.61). what was her estimate?
–250
–240
240
250

If she used rounding properly, she would have gotten -25 x 10 = -250

When rates are expressed as a quantity of 1, such as 2 feet per second or 5 miles per hour, they are called unit rates. if you have a multiple-unit rate such as 120 students for every 3 buses, and want to find the single-unit rate, write a ratio equal to the multiple-unit rate with 1 as the second term.