We can use blocks to make numbers. When we're using blocks we need to think about how many numbers are in each block.
We can start with one block which represents $1$1 unit.
If we put $10$10 unit blocks together we get $10$10 units.
If we put ten $10$10 unit blocks together we get $100$100 units!
$1$1  $10$10  $100$100 

We can use blocks to make whole numbers. If we want to make the number $7$7 we can use $7$7 unit blocks.
$+$+ $+$+ $+$+ $+$+ $+$+ $+$+ $=7$=7
Let's use the blocks to make the number $117$117.
How many hundreds, tens and units (ones) are there in the number $117$117?
$117$117 


Use the blocks to make the number $5$5
Use the least amount of blocks possible to make the number $21$21
Use the least amount of blocks possible to make the number $312$312