One Decimal Place Rounding Tool

Enter Number

Common Examples: Rounding to One Decimal Place

Original Number	Rounded to 1 Decimal	Explanation
3.456	3.5	Second decimal (5) rounds up
12.34	12.3	Second decimal (4) < 5, rounds down
7.89	7.9	Second decimal (9) ≥ 5, rounds up
99.95	100.0	Rounds up to next whole number
0.123	0.1	Second decimal (2) < 5, rounds down
5.678	5.7	Second decimal (7) ≥ 5, rounds up

How to Round to One Decimal Place

Rounding to one decimal place means keeping exactly one digit after the decimal point. This is commonly used for temperature readings, grade point averages, sports statistics, and simplified data presentation.

Why Round to 1 Decimal Place?

Temperature: Weather reports often use one decimal (e.g., 72.5°F)
GPAs: Many schools report GPAs to one decimal (e.g., 3.7)
Sports Stats: Batting averages, ERA, and other metrics
Ratings: Product or service ratings (e.g., 4.5 stars)
Simple Estimates: Easy to read and communicate

Step-by-Step Rounding Process

Step 1: Identify the First Decimal Place

In the number 3.456, the first decimal place is "4" (the tenths position).

Step 2: Look at the Second Decimal

The second decimal digit determines rounding direction. In 3.456, the second decimal is "5".

Step 3: Apply the Rounding Rule

If the second decimal is 5 or greater, round UP. If less than 5, round DOWN. Since 5 rounds up, result is 3.5.

Step 4: Keep Only One Decimal

Drop all digits after the first decimal place. Final result: 3.5

Common Use Cases

Temperature: 72.456°F rounds to 72.5°F for weather forecasts

GPA: 3.678 grade point average becomes 3.7 GPA

Batting Average: .3456 rounds to .345 (displayed as .345)

Product Ratings: 4.67 stars rounds to 4.7 stars

Fuel Economy: 28.456 MPG rounds to 28.5 MPG

Understanding Tenths

Place value: The tenths place represents 1/10 or 0.1

Fraction equivalent: 3.5 = 3 and 5/10 = 3½

Common fractions: 0.5 = ½, 0.3 = 3/10, 0.7 = 7/10

Real-World Applications

Weather: Temperature, precipitation amounts, wind speed

Education: GPAs, test score averages, course ratings

Sports: Batting averages, ERA, points per game

Consumer: Star ratings, fuel efficiency, unit prices

Quick Reference

What is one decimal place? The tenths position, or 1/10 precision

Key digit: Look at the second decimal place (hundredths)

Standard use: Temperature, GPAs, ratings, and simplified data