A bundle of ten: place value
Read numbers from 10 to 20 as tens and ones.
Start with the objects ↓An idea to revisit first: What remains: subtraction →
Think with objects in front of you
Make one bundle of ten. One bundle and three loose objects make thirteen, written 13.
After counting ten objects, arrange them in one row. They have not disappeared; bundling is a clearer way to organize the same amount.
One bundle and three loose objects make thirteen. In 13, the left digit 1 means one ten; the right digit 3 means three ones.
The 0 in 10 says there are no loose ones. It does not erase the bundle of ten. The positions of the digits make 10 different from 1.
Ten more loose objects can form another bundle. Two tens and no ones make 20. Bundling or unbundling does not change the total quantity.
Listen one paragraph at a time
Now move the objects yourself
Change the count from 11 to 19. Look for the row of ten and the loose ones. At 20, count the complete rows.
Tap objects to mark what you have counted. There is no time limit.
One ten
Ones
You may use small toys or blocks instead of the screen. Explain what stayed the same and what changed.
Check your idea with different examples
What do the digits 1 and 4 mean in 14?
You may speak or draw on paper. Look for these ideas in your explanation.
Continue reading, or pause here
You can also make equal groups of two or three instead of ten.