AI Tutor
Imagine you have a jar filled with 100 shiny marbles. Counting them one by one takes forever!
What if we grouped them by tens to count up to 100 in just a few seconds?

Trading Rods for a Flat

A single long block is called a rod, and it is made of 10 small unit cubes.
When you line up 10 rods side by side, they fit together into a big square called a hundred flat.
How do we know for sure that 10 rods really equal 100 small cubes?

Counting by Tens

We can prove it by skip counting each rod by tens: 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100.
Because ten groups of 10 total 100, 10 tens make 1 hundred.
Can we accidentally mix up unit cubes and rods when building big numbers?

Cubes, Rods, and Flats