Reading and Writing Numbers up to 100
In this video, we will learn how to model, read, and write numbers to 100 in digits and words. We can write numbers using digits or words. The two-digit numbers up to 100 have an amount of tens and ones. We can model these numbers using maths equipment, like ten frames or place value blocks.
What number is shown in this model? This is a ten frame. And it’s full; it has 10 counters. We can write this in our place value chart. Our number has one ten. We call these counters the ones. This is because the ten frame is not yet full; it has less than 10 counters.
How many ones are there? Did you count? There are eight ones. One ten and eight ones is 18. How would we write this number in words? 18 is a teen number. These are the numbers between 10 and 20. Let’s practice writing the teen numbers in words. Eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen. This is how we write 18 in digits, and this is how we write 18 in words.
When we write numbers between 20 and 100 in words, we need to use a tens word and a ones word. The tens digit in the number 65 is worth 60. Six tens are 60. So, our tens word is 60. And the five digit in 65 is worth five ones. So, our ones word is five. We wrote the number 65 in digits and words.
How would we write the number 49 using digits? We write 40 as four tens and the nine as nine ones. This is how you write the number 49 in digits. The four tens are worth 40, and the nines digit is worth nine ones. We wrote the number 49 in digits and words. Let’s practice modeling, reading, and writing numbers to 100 in digits and words.
Noah and Emma tried to read the number given. Emma said it is 74, and Noah said it is 47. Who said the right answer?
Noah and Emma are trying to work out which number is shown in the model. We know it’s a two-digit number because it has an amount of tens and ones. Emma thinks the number is 74, and Noah thinks the number is 47. Let’s count the tens and ones to find out who’s right.
How many tens are there in the tens part of this number? One, two, three, four, five, six, seven. So, we can write a seven in the tens place. Did you count the ones? There are four. Seven tens and four ones is 74. So, Emma was right. It looks like Noah wrote the tens and ones digits the wrong way round. The number given is 74. So, Emma was right.
Write the given number in words.
We’re shown a two-digit number. And we have to write it in words. How many tens does this number have? One, two, three, four, five, six. We have six tens. Now, let’s count the ones. One, two, three, four, five, six, seven. Six tens and seven ones. We’ve written the number in digits. The number is 67. Six tens are 60. 10, 20, 30, 40, 50, 60. And this is how we write 60 in words. This is the tens part of the number, 60.
And we know that the ones part of the number is worth seven. This is how we write seven in words. The given number is 67. And this is how we write it in words.
Daniel writes fifty-seven in words. Write that number in digits.
Daniel has written the number fifty-seven using words. Now, we have to write the same number using digits. The tens part of Daniel’s number is fifty. We can model fifty using five tens. 10, 20, 30, 40, 50. Daniel’s number has five tens, worth 50, and seven ones. We wrote the number 57 using digits. Five tens and seven ones is 57.
Write the number 85 in words.
We can model the number 85 using eight tens. Eight tens are 80. 10, 20, 30, 40, 50, 60, 70, 80. 85 has eight tens and five ones. We know the tens part of the number 85 is worth 80. And this is how we write five in words. The tens part of the number is 80, and the ones part is five, 85. We wrote the number 85 in words.
What have we learned in this video? We learned how to model, read, and write numbers up to 100 in digits and words.