Module 1, Lesson 7: Round Multi-Digit Numbers to the Thousands Place Using the Vertical Number Line

Today we are going to beginrounding numbers on a vertical number line. In this lesson specifically, we are going to look at rounding numbers to the thousands place.First, we start by drawing our vertical number line. When we label the number line, we have to start with two endpoints. Endpoints are the highest point on the number line and the lowest point on the number line. After the endpoints are labeled, a midpoint needs to be labeled. The midpoint is the number halfway between the two endpoints.For example; If I am looking at the number 3,600, the highest endpoint would be 4,000 and the lowest endpoint would be 3,000. Halfway between 3,000 and 4,000 is 3,500, so that is my midpoint.For this lesson, we are rounding to the nearest thousand so we are choosing the higher thousand and the lower thousand as our endpoints. In the example I showed, the higher thousand of 3,600 is 4,000. The lower thousand of 3,600 is 3,000.When rounding numbers, we need to look to the digit to the right of the highest place value number. When the number is 4 or less, we round to the lowest endpoint. When the number is 5 or more, we round to the highest endpoint.In the example number 3,600, we would round to the highest endpoint because 6 is more than 5.Here are a couple rules for rounding numbers:1. Look at the number that has the highest place value; or the number all the way to the left.2. Think of what 1 more ten, hundred,thousand, ten thousand, hundred thousand or million is, that number is the highest endpoint.3. Think of what 1 less ten, hundred,thousand, ten thousand, hundred thousand or million is, that number is the lowest endpoint. 7,000 9,000 16,000 40,000 399,000 840,000 7,000 6,000 6,500 10,000 9,000 9,500 17,000 16,000 16,500 40,000 39,500 39,000 400,000 399,500 399,000 850,000 840,500 840,000