WEBVTT
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Comparing Two-Digit Numbers: Place Value
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In this video, we will learn how to compare numbers up to 100 by comparing the number of tens and ones.
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Two-digit numbers have a tens digit and a ones digit.
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This number has one 10.
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We’ve grouped the 10 ones together into a tower.
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This is called a 10.
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And our number has six ones.
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10 and six make 16.
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The tens digit in the number 16 is the one.
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The one is worth one 10.
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And the six digit in the number 16 is worth six ones.
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One 10 and six ones makes the number 16.
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Let’s try some practice questions.
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By looking closely at the tens and ones digits, we can compare the value of two or more numbers.
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Mason has written 31 and 39 in a place value table.
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Does 39 have more, less, or the same number of 10s as 31?
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Does 39 have more or less ones than 31?
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Pick the smaller number.
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31 or 39?
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In this question, Mason is comparing two numbers.
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They are the numbers 31 and 39.
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They’re both two-digit numbers.
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In the first part of the question, we need to compare the amount of tens in both numbers.
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And in the second part of the question, we need to compare the amount of ones in both numbers.
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Let’s start by looking at the tens digit.
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This is in the column called tens.
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We can see that the number 31 has three 10s and the number 39 also has three 10s.
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So we can say that 39 has the same number of 10s as 31.
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Now, we need to compare the amount of ones in each number.
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We can see that the number 31 has one in the ones place and the nine in 39 is worth nine ones.
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Nine is more than one.
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So we can say that 39 has more ones than 31.
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So which is the smaller number, 31 or 39?
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It’s number 31.
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Both numbers have three 10s.
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But number 31 only has a one in the ones place.
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39 has nine ones.
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And we know that nine is more than one.
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So number 39 has the same number of 10s as 31, and 39 has more ones than number 31.
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The smaller number is number 31.
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Which is greater, 97 or 77?
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In this question, we’re being asked to compare two two-digit numbers.
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We can use place value tables to help us compare these two numbers.
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The number 97 has nine 10s and seven ones.
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And the number 77 has seven 10s and seven ones.
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Let’s start by comparing the ones digit.
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Both numbers have seven ones.
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97 and 77 both have seven ones.
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Let’s compare the tens digit.
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Let’s compare the tens digits now.
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97 has nine 10s.
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10, 20, 30, 40, 50, 60, 70, 80, 90.
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Nine 10s makes 90.
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And the number 77 has seven 10s.
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10, 20, 30, 40, 50, 60, 70.
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Which of our two-digit numbers has the most 10s?
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The number 97.
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It has nine 10s.
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And 77 only has seven 10s.
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So number 97 is greater than 77.
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Hannah made three numbers with place value cards.
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20 plus eight is 28, 50 plus two is 52, and 50 plus seven is 57.
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Pick the correct number sentences.
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Remember, to compare 28 and 52, we compare the tens digit.
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Is 28 equal to 52, less than 52, or greater than 52?
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57 and 52 have the same tens digit.
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Compare the ones digit to find the correct number sentence.
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57 is less than 52, equal to 52, or greater than 52.
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Which is the greatest number that she made?
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This is a three-part question.
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In the first part of the question, we need to compare the numbers 28 and 52.
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We’re told how to do this.
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By comparing the tens digits.
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And if we look closely at the place value cards, we can see that 28 has two 10s and 52 has five 10s.
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We know that five is more than two, so 52 must be greater than 28 because 50, or five 10s, is greater than 20 which is two 10s.
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So 28 is less than 52.
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In the second part of the question, we have to compare the numbers 57 and 52.
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And we’re told to do this by comparing the ones digit.
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This is because 57 and 52 both have the same number of 10s.
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They both have five 10s.
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Let’s compare the ones.
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52 has two ones.
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57 has seven ones.
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And we know that seven is greater than two, so we can say that 57 is greater than 52.
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So which is the greatest number that Hannah made?
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It’s the number 57.
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57 has five 10s and seven ones; 28 only has two 10s.
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And although 52 has five 10s, it only has two ones.
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57 has the most 10s and ones.
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What have we learned in this video?
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We’ve learned how to compare two-digit numbers by comparing the number of 10s and ones.