Know how to count

1 one
10 ten
100 one hundred
1000 one thousand
10 000 ten thousand
100 000 one hundred thousand
1 000 000 one million
1 000 000 000 one billion

Hundred AND

125 one Hundred AND twenty-five
536 five Hundred AND thirty-six
999 nine Hundred AND ninety-nine

Thousand AND

1200 one thousand two hundred
2500 two thousand five hundred
43200 forty-three thousand two hundred

Hundred AND thousand together

3245 three thousand two hundred AND forty-five
65748 sixty-five thousand seven hundred AND forty-eight