1st Grade Math
Place Values
Unit 1
Watch this awesome video for an introduction into place values!
DIGITS
What is a digit? A digit is any number between 0 and 9. 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 are all digits. What do you notice about the difference between 8 and 18? If you said that 18 has two digits and 8 has 1 digit, you'd be right! 18 has the digits 1 and 8 inside of it, while 8 only has, well, the digit 8. Recognizing digits is the first step to understanding place values.
How many digits does this number have? 3
One digit
How many digits does this number have? 24
Two digits, 2 and 4
PLACE VALUES
Right now, we are just going to learn the tens place and the ones place. If there are 2 digits in a number, then there is a digit in the tens place and the ones place. If you read a number from right to left, then the number in the right-most (the one furthest to the right) position is in the ones place. The number to the left of that is in the tens place. Let's look at an example. Take the number 23. In 23, the digit 3 is the rightmost digit, so it is in the ones place. The digit 2 is to the left of 3, so it is in the tens place. If there is 1 digit in a number, then that number is just in the ones place.
The tens place means that there are 10 ones in that position. This is why digits are only between 0 and 9 because 10 has 2 digits, 1 and 0! Since we have really big numbers that exist, we have to put a 1 in the tens place and a 0 in the ones place so it doesn't get confusing.
Which digit is in the ones place? 14
4
Which digit is in the tens place? 62
6
Which digit is in the tens place? 810592
9, this is because it is the number directly to the left of the rightmost number, which is 2
52
Look at the figure! It has 4 tens and 12 ones. 40 + 12 = 52
52
Look at the figure! It has 5 tens and 2 ones. 50 + 2 = 52
It's okay if you don't get this right away, it's confusing sometimes! Hopefully this video makes it clearer! -->
Comparing Numbers
So, how do we apply this place value knowledge? We can do it by first comparing numbers!
Let's take the numbers 23 and 42. What do these represent?
In 23, there are 2 tens and 3 ones.
In 42, there are 4 tens and 3 ones.
Using place values, you can only compare if they have the same unit (tens or ones, in this case). A ten means that there are 10 ones, so tens are bigger than ones. So, we can compare these numbers by looking at the tens only! Since 4 is greater than 2, that means that 42 is bigger than 23.
But what if they have the same tens digit? That is when we can look at the ones place. Take the numbers 24 and 28. The tens place digit for both is the same, but the ones place digits are not. Since 8 is a bigger digit than 4 is, we can say that 28 is bigger than 24.
Which number is bigger? 62 or 92
92 is bigger because the tens place digit, 9, is bigger than the other number's tens place digit, 6.
Which number is bigger? 16 or 4
16, because it has a tens place digit, 1, while the other number, 4, does not.
Which number is bigger? 33 or 37
37 because although the tens place digit, 3, is the same, the ones place digit, 7 is bigger than the other number's ones place digit, 3.
Try this fun game for place value practice!
Try this fun game for place value practice!
Let's Try It Together!
Watch the video below for an example!
Place Values.mp4