Use place value understanding to round multi-digit whole numbers to any place.
Official wording from the Common Core State Standards for Mathematics (Β© 2010 National Governors Association Center for Best Practices and Council of Chief State School Officers). View on thecorestandards.org
Rounding replaces a number with a nearby, friendlier one. To round 46,381 to the nearest thousand, students ask which two thousands it sits between (46,000 and 47,000) and which one it is closer to. Because 46,381 is less than halfway (46,500), it rounds down to 46,000. In third grade students rounded to the nearest 10 or 100; in fourth grade they round to any place, from tens to hundred thousands.
The standard emphasizes place value understanding over a memorized rule. A vertical or horizontal number line with the two benchmark numbers and the halfway point shows why the digit to the right matters: it tells you which side of the midpoint you are on. When a number is exactly halfway, the convention is to round up. Rounding is the main tool for estimating, which students use to check calculations in 4.OA.A.3. Knowing which place to round to is a judgment call, and students should practice choosing a place that makes the estimate both easy and useful.
To round to the nearest thousand, students sometimes check the thousands digit itself. The deciding digit is the one just to the right, in the hundreds place.
Rounding 5,682 to the nearest hundred as 5,600 or 6,000 shows confusion about which places stay. Only the rounding place may change, and everything to its right becomes zero.
Rounding 3,970 to the nearest hundred gives 4,000, not 3,1000. When a 9 rounds up, the change carries into the next place.
Round 284,519 to the nearest ten thousand.
Answer: 284,519 rounded to the nearest ten thousand is 280,000.
Begin every rounding problem by writing the two candidates and the midpoint on a number line. Students who do this consistently stop making place errors, and the shortcut of checking the next digit then makes sense as a description of the number line.
Questions often ask for a number that rounds to a given value, such as "Which number rounds to 7,000 when rounded to the nearest thousand?" Reverse questions like these test real understanding and are worth practicing.
Original questions written for this standard. Choose an option or type your answer, then press Check. Every question has a worked explanation.
Answer: 6500 (also accepted: 6,500)
6,482 is between 6,400 and 6,500. The tens digit is 8, so it is past halfway (6,450). It rounds up to 6,500.
Answer: 74000 (also accepted: 74,000)
73,615 is between 73,000 and 74,000. The hundreds digit is 6, past halfway, so it rounds up to 74,000.
Answer: C) 4,602
4,602 is between 4,000 and 5,000 and past the halfway point 4,500, so it rounds up to 5,000. 5,512 and 5,500 round to 6,000, and 4,499 rounds to 4,000.
Answer: 4000 (also accepted: 4,000)
3,970 is between 3,900 and 4,000. The tens digit is 7, so it rounds up. 39 hundreds becomes 40 hundreds, which is 4,000.
Answer: A) 500,000
451,206 is between 400,000 and 500,000. The ten thousands digit is 5, so it is at or past halfway and rounds up to 500,000.
Answer: 8050 (also accepted: 8,050)
8,045 is exactly halfway between 8,040 and 8,050. By convention, halfway rounds up to 8,050.
A full lesson with slides, activities and an exit ticket on rounding multi-digit numbers, pitched to grade 4 and editable in PowerPoint or Google Slides.
Make a lesson βA printable, differentiated worksheet on 4.NBT.A.3 with an answer key, ready in about a minute.
Make a worksheet βTurn rounding multi-digit numbers into a quiz students answer online that marks itself, with a class summary for you.
Build a test βThe usual convention in school math is to round up. For example, 650 rounded to the nearest hundred is 700.
A number line shows which benchmark a number is closer to, so students understand rounding rather than just following a digit rule, which helps them avoid place errors.