Determine Endpoints and Midpoint for Rounding to the Thousands
This Grade 4 Eureka Math skill teaches students to determine the lower endpoint, upper endpoint, and midpoint needed for rounding any number to the nearest thousand. Students identify the nearest lower thousand and upper thousand surrounding a given number, then calculate the midpoint by adding 500 to the lower thousand. For example, for 4,821, the lower thousand is 4,000, the upper is 5,000, and the midpoint is 4,500. This skill, from Chapter 3 of Eureka Math Grade 4, builds the conceptual foundation for all thousand-place rounding decisions.
Key Concepts
To round a number to the nearest thousand, first find the nearest lower thousand and the nearest higher thousand. The midpoint is the number in the middle between them.
The upper thousand is $1000$ more than the lower thousand:.
Common Questions
How do you find the lower and upper thousands for a number?
The lower thousand is the greatest multiple of 1,000 that does not exceed your number. The upper thousand is 1,000 more than the lower thousand. For 4,821, lower is 4,000 and upper is 5,000.
How do you calculate the midpoint between two thousands?
Add 500 to the lower thousand. The midpoint between 4,000 and 5,000 is 4,000 + 500 = 4,500.
What is the midpoint between 27,000 and 28,000?
27,000 + 500 = 27,500. The midpoint is always 500 more than the lower thousand in the pair.
Why is the midpoint important when rounding to the nearest thousand?
The midpoint is the decision boundary. Numbers below the midpoint round down to the lower thousand; numbers at or above the midpoint round up to the upper thousand.
What is the midpoint between 156,000 and 157,000?
156,000 + 500 = 156,500. A number exactly at the midpoint, like 156,500, rounds up to 157,000.