Rounding from the Midpoint to the Nearest Thousand
This Grade 4 Eureka Math skill teaches the rounding rule for numbers that fall exactly at the midpoint between two thousands: they always round up to the greater thousand. The midpoint between any two consecutive thousands is found by adding 500 to the lower thousand. For example, 4,500 (midpoint between 4,000 and 5,000) rounds up to 5,000, and 27,500 rounds up to 28,000. This convention, covered in Chapter 3 of Eureka Math Grade 4, ensures consistent results when rounding multi-digit numbers to the nearest thousand.
Key Concepts
When rounding to the nearest thousand, a number that is exactly at the midpoint between two thousands always rounds up to the greater thousand. The midpoint is found by adding 500 to the lower thousand.
Common Questions
What happens when a number is exactly at the midpoint between two thousands?
It always rounds up to the greater thousand. For example, 4,500 is exactly halfway between 4,000 and 5,000, so it rounds up to 5,000.
How do you find the midpoint between two consecutive thousands?
Add 500 to the lower thousand. The midpoint between 27,000 and 28,000 is 27,000 + 500 = 27,500.
Does 27,500 round to 27,000 or 28,000?
27,500 rounds up to 28,000 because it is exactly at the midpoint, and the rule is to always round up at the midpoint.
Why do midpoint numbers always round up?
This is a standard mathematical convention to ensure consistency. When a number is equidistant between two options, rounding up gives a definitive, predictable rule.
What is the midpoint between 156,000 and 157,000?
156,000 + 500 = 156,500. Any number at or above 156,500 rounds up to 157,000; any number below rounds down to 156,000.