And now with the big story on comparing and ordering whole numbers, your

Transcription

1 Comparing and Ordering MA6131 Activity Introduction And now with the big story on comparing and ordering whole numbers, your anchorman, Daaaaaan Anchormann. Direct Instruction Thanks, Big Al. Let s get right to it. Today we re gonna learn two methods of comparing and ordering numbers. Comparing and ordering numbers is used not only in math, but also in science, history or even sports. For example, by ordering numbers, we can find which planet is farthest from the sun or closest to the sun. For more help on the subject, here s our resident expert: Lord Rottington. Model 1 We will first discuss using a number line to compare and order whole numbers. When you are using a number line to compare numbers, the la-la-la-least or smallest number is the one farthest to the la-la-la-left. The greatest or largest number is the one farthest to the right. So, what if I wanted to compare the number of cups of tea I drank yesterday to the number I drank today?

2 Yesterday I drank twenty-five cups and today I drank twenty-seven cups. Oh my, that s quite a lot of tea. So my problem looks like this.i begin by making a number line. If I start my number line with one, I ll be here forever Twenty-five and twenty-seven are between twenty and thirty. Now with the number line, you can mark the places for twenty-five and twenty-seven. Now I can answer the problem easily. Twenty-five is less than twenty-seven. I think I drink too much tea. Let s pause here for a moment. So do you think you can compare two numbers using a number line? If you re not sure, we can go through this again. Model 2 Now that you re an expert at comparing numbers using a number line, let s go back to Lord Rottington to learn about putting those numbers in order. You may not know this about me, but I am a big fan of order. There is a place for everything and everything in its proper place. For numbers, the proper order is from least to greatest. Let's work a problem on a number line to find out the proper order of these numbers. First, let s make our number line. It seems that starting at four hundred twenty and going by tens to four hundred forty should work nicely. Next, let s place the numbers on the number line. Now we can tell the order the numbers should be in. The order from least to greatest is four hundred twenty-two, four

3 hundred twenty-seven, four hundred twenty-nine, four hundred thirty, and four hundred thirty-five. Order. Hooray.I ordered Lord Rottington to pause here to make sure that you re getting all of this. If you do get all of this, let s move ahead. If you want to review ordering numbers using a number line, I can just rewind it for you. Direct Instruction I think you ve mastered comparing and ordering numbers using a number line. Now let s check out another method. We re gonna work on putting numbers in order using place values. Let s go back to Lord Rottington at his estate for more. Model 1 Allow me to demonstrate how we put numbers in order using place values. The first step in comparing and ordering numbers is creating a place value chart like the one you see here. This helps me to easily visualize and determine the value of the numbers I want to compare. This is particularly helpful with rather large numbers. Let s compare two million twenty-two thousand four hundred three and two million twenty-three thousand one hundred one. See how I placed the numbers on the chart, digit by digit?

4 Now we compare the numbers beginning with the largest place value. In the million, hundred thousand, and ten thousand places the digits are the same. Notice in the thousand place, three is greater than two. We can easily see that two million twenty-two thousand four hundred three is less than two million twenty-three thousand one hundred one. Did that make sense to you? If so, let s keep going. If not, I can easily show you that lesson again. Model 2 Great! I know Lord Rottington is geared up to start talking about order. Let s go back to him. Let s take our handy place value chart to help us out with this next problem. Arrange these numbers in order from least to greatest. First, insert each number in the place value chart. Then, begin comparing the digits from the left to the right like we did before, comparing the largest place value first. In the billion column, five is the larger number. That means the number with five billion is the largest. Let s put that in our answer. Now let s figure out the order of the remaining numbers. When we compare each digit of the remaining numbers, we see they are the same in the billion and the hundred million column. However, when we move on to the ten million column, we see they are different.

5 Six is less than eight, so that number is the smallest. Let s put that number in the answer. We can go ahead and put that last number in the answer now. Now we have achieved order!did you get all that? If not, I d be happy to engage the ole rewindinator so you can work that problem out again with Lord Rottington. End of Activity Review So, let s take another look at what we learned today: In this lesson you learned two methods to compare and order whole numbers. The first method was to place the numbers on a number line. Remember, the number farthest to the right on the number line is the greater number. The second method was to place the numbers in a place value chart. When the numbers are lined up by their place value, you can compare the digits from the left to the right. Then you re all set to just put the numbers in order.lord Rottington, did I miss anything? I think you ve covered everything, Daniel. Well done. Now please let me get back to my book. That s our Lord Rottington! Alright, take some time to think about comparing and ordering numbers. Let me know when you re ready to move on.