Атрибуты method, action и <input type='submit'>.
А конкретнее method='POST' action='post.php' и <input type='submit'> внутри формы
11 девочек м 10 мальчиков.
<span>1011= 1*2^3+0*2^2+1*2^1+1*2^0=8+0+2+1=11
</span>1010= 1*2^3+0*2^2+1*2^1+0*2^0=8+0+2+0=10
JS
ECMA 6
let number = prompt("Give me a number")
if(number < 20 && number > 10) console.log(`${number} is in range of (10, 20)` )
else console.log(`${number} is not in range of (10, 20)`);