Q&A for How to Round Numbers

Typically, the rule for rounding numbers is "4 or less, round it down. 5 or more, round it up."

10.2499 cm.

"Three significant figures" refers to the first three digits starting from the left. So, you round the third digit up or down depending on what the fourth digit is. Since the fourth digit is "5," you would round the third digit up. That leaves you with 20,100.

The closer you round to a whole number, the less accurate the number becomes. For example, "2.345678" is more accurate than "2.3457." In a lot of simple real-world cases, this doesn't matter, but for scientific or engineering purposes, you will need to be as accurate as possible, so there will either be no rounding, or rounding to a much higher decimal place.

Rounding off is a way to simplify a number by shortening it to fewer significant digits without changing its value very much. An example is rounding 1,096 (four significant digits) up to 1,100 (two significant digits).

0.900 has been rounded to the nearest tenth. In order to round 0.867 to the nearest thousandth, you would need another digit to the right of the 7.

0.231.

If you keep rounding up beginning with the right-most digit, you wind up with 3.000 in four significant digits.

0.314 = 314 / 1000.

526,700.

If we want to round to 2 decimal places, we must look at the thousandths place. Here, the number is five so we have to round the number in the hundredths place upwards. Therefore, your answer should be 12.36.

There is no universally agreed-upon rule about rounding negative numbers. Some people would round -20.5 to -20. Others would round to -21. If you have a teacher, ask that person what the preference is. Otherwise, round up or down as you like. There are good arguments either way.

There's no such thing as rounding by 15. You round to the nearest one, ten, hundred, thousand, etc., or to the nearest tenth, hundredth, thousandth, etc.

Because 3 is less than 5, it rounds down to zero.

The hundreds' column is the third column from the right. So you look at the tens' column, which has a 3. So you round the hundreds' column down to the nearest hundred: 29,000.

That number is four-tenths.

Because there is no thousand's place, there's no such thing here. You can round to the nearest hundred, making it 500.

Round up to 50.

Because of the 7, round up to 2360.

Because of the 8, round up to 330.

If the "rounding number" is 0, it will either remain 0 or round up to 1, depending on the number immediately to the right.

Rounding to the nearest tenth, it becomes 4.8.

No, it's 1.76. The 2 means that the 6 remains instead of being rounded up to 7. So 1.7623 is "rounded down" to 1.76.

When rounding to the nearest ten's digit, 12 always rounds down to 10 (no matter what the digits are to the right of the decimal point). If you are asking about the nearest tenth's digit (the 7 in this example), the 9 causes all of the 4's to round up to 5, which causes the 7 to round up to 8. So in this case rounding to the nearest tenth results in 12.8.

Round it according to whatever instructions are given with the question.