Numbers to 40

Type 21 in words.

Type 40 in words.

Type 37 in words.

Type 28 in words.

What number is this?

What number is this?

 $30\ +\ 5\ =?$  

 $20\ +\ 1\ =\ ?$  

27 = ___ tens ____ ones

• 27 tens 0 ones

• 2 tens 7 ones

• 7 tens 2 ones

• 2 tens 0 ones

40 = ___ tens ___ ones

• 0 ten 4 ones

• 40 tens 1 ones

• 4 tens 0 ones

• 0 ten 0 one