Rounding to the Nearest Thousand, Ten Thousand, and Hundred Thousand
Rounding to the Nearest Thousand, Ten Thousand, and Hundred Thousand is a Grade 4 math skill that extends rounding to larger place values using benchmark numbers and midpoints. To round 36,812 to the nearest thousand, find the two benchmarks (36,000 and 37,000), calculate the midpoint (36,500), and since 36,812 is above the midpoint, round up to 37,000. Covered in Chapter 3: Rounding Multi-Digit Whole Numbers in Eureka Math Grade 4, this skill is essential for estimation and checking reasonableness of answers in multi-step word problems.
Key Concepts
Property To round a number, first find the two benchmark numbers (e.g., the two thousands) it is between. Then, find the midpoint. If the number is greater than or equal to the midpoint, round up to the next benchmark. If the number is less than the midpoint, round down to the lower benchmark.
Examples To round $36,812$ to the nearest thousand: The number is between $36,000$ and $37,000$. The midpoint is $36,500$. Since $36,812 \geq 36,500$, we round up to $37,000$. To round $124,500$ to the nearest ten thousand: The number is between $120,000$ and $130,000$. The midpoint is $125,000$. Since $124,500 < 125,000$, we round down to $120,000$. To round $750,000$ to the nearest hundred thousand: The number is between $700,000$ and $800,000$. The midpoint is $750,000$. Since $750,000 \geq 750,000$, we round up to $800,000$.
Explanation This skill involves rounding larger numbers to a specific place value like the thousands, ten thousands, or hundred thousands. First, you identify the two multiples of that place value that your number falls between. Then, you determine the halfway point, or midpoint, between them. If your number is at or above the midpoint, you round up; otherwise, you round down.
Common Questions
How do I round a number to the nearest thousand?
Find the two multiples of 1,000 the number falls between. Calculate the midpoint between them. If your number is at or above the midpoint, round up; if below, round down. For example, 36,812 rounds to 37,000 because it is above the midpoint of 36,500.
How do I round to the nearest ten thousand?
Find the two multiples of 10,000 the number falls between, then check where your number sits relative to the midpoint. For 124,500, the benchmarks are 120,000 and 130,000 with midpoint 125,000. Since 124,500 is less than 125,000, round down to 120,000.
What is a benchmark number in rounding?
Benchmark numbers are the two round numbers your target number falls between. When rounding to thousands, the benchmarks are consecutive multiples of 1,000. When rounding to ten thousands, the benchmarks are consecutive multiples of 10,000.
What happens when a number is exactly at the midpoint?
By convention, when a number equals the midpoint between two benchmarks, you round up. For example, 750,000 rounded to the nearest hundred thousand rounds up to 800,000 because 750,000 equals the midpoint between 700,000 and 800,000.
Why is rounding large numbers an important Grade 4 skill?
Rounding large numbers helps with estimation — quickly checking whether an answer is in the right range. It is used in real life for budgeting, measuring distances, and understanding large quantities like population figures or distances in space.
What chapter covers rounding large numbers in Eureka Math Grade 4?
Chapter 3: Rounding Multi-Digit Whole Numbers in Eureka Math Grade 4 covers rounding to thousands, ten thousands, and hundred thousands using number lines, benchmarks, and the midpoint rule.