Round each number in the question to only have one non-zero digit. For example, 64 becomes 60, and 1,890 becomes 2,000. Then do the calculation required. More »

It is useful to be able to estimate quotients because a long division by hand is not necessary with this method. Instead, students can calculate easily an estimated answer to complex division problems through the use of ... More »

A mixed number contains a whole number and a fraction. To estimate fractions with mixed numbers, add the benchmark of the fraction to the whole number. More »

Students practice front end estimation with adjustment by rounding numbers before adding them. For estimating an addition problem that involves hundreds, the student rounds each number to the closest hundred and then add... More »

Front end estimation involves rounding off a number to the leftmost place and using that in the addition problem. With front end estimation, 43 + 52 becomes 40 + 50; 43 is rounded down to 40, and 52 is rounded down to 50... More »

As a general rule of thumb, numbers should be rounded down if the final digit in a number is from 0 to 4, and rounded up if it's 5 to 9. Rounding sometimes involves more than one digit; some situations may call for round... More »

To perform partial product multiplication, you use the distributive property of numbers, multiplying each digit of a number by each digit of the other number and adding the results while taking the place value of each di... More »