Bài 10: Introducing ninety to ninety nine

Starry, are you getting ready for you first day at school.

So many books to cover, come, let me help!

These books have 25 pages each and these have 50 pages.

You look worry, you can’t find the book with 90 pages. It’s right here Starry.

Look, 9 and 0, 90. Oh, you haven’t learnt the number 90 yet.n-i-n-e-t-y, Starry, 90.

Now let me explain the number 90 to you.

Each pile of book has 10 books in it. That ten+ ten+ten+ten+ten+ten+ten+ten+ten, 9 tens, 90 books.

Starry, suppose we add a single book to these pile of books. We get 9 tens 1, which is 91, n-i-n-e-t-y o-n-e.

On adding 2 books, we get 9 tens 2 that’s 92, n-i-n-e-t-y t-w-o, 92.

When 1-2-3 books are added Starry to the 9 pile of books, it forms 9 tens 3, which is the number 93, n-i-n-e-t-y t-h-r-e-e, 93.

Now 9 tens plus 4 books gives us 9 tens 4, which is the number 94, n-i-n-e-t-y f-o-u-r.

And 9 pile of book plus 5 books is 9 tens 5 which forms the number 95, n-i-n-e-t-y f-i-v-e, 95.

When we add 1 more book, we get 9 pile of books plus 1-2-3-4-5-6 books that 9 tens 6, which is the number 96, n-i-n-e-t-y s-i-x, 96.

Now 9 pile of books plus 1-2-3-4-5-6-7 books is 9 tens 7, that is the number 97, n-i-n-e-t-y s-e-v-e-n, 97.

Starry, here are 9 pile of books plus 8 single book that’s 9 tens 8, 98, n-i-n-e-t-y e-i-g-h-t, 98.

And 9 pile of books and 9 single books is 9 tens 9, 99, n-i-n-e-t-y n-i-n-e, 99.

Starry, let’s count the numbers in the ascending order from 90 to 99. That’s 90-91-92-93-94-95-96-97-98-99.

And in the descending order 99-98-97-96-95-94-93-92-91-90.

Now let’s do an activity together!

Identify the numbers and write the number names.

9 and 3, 93, n-i-n-e-t-y t-h-r-e-e

9 and 8, 98, n-i-n-e-t-y e-i-g-h-t

9 and 2, 92, n-i-n-e-t-y t-w-o

9 and 7, 97, n-i-n-e-t-y s-e-v-e-n

9 and 9, 99, n-i-n-e-t-y n-i-n-e

9 and 0, 90, n-i-n-e-t-y

And in this activity Starry, the numbers are all jumble up.

We have to first put them to the correct in the ascending order from the smallest to the biggest, and then in the descending order from the biggest to the smallest.

Shall we begin!

The first number is 9 and 0, 90 then we have 91-92-93-94 next 95-96-97-98 and lastly 99.

And now Starry, in the descending order 99-98-97-96-95-94-93-92-91and 9 and 0, 90.

Starry, if you see the number 9 and 0 anywhere, remember it stands for the number 90.

The numbers that follow are 91-92-93-94-95-96-97-98 and 99.