13806 : 531 = 26
$\snippet{name: long_division, x: 13806, y: 531}$
 
30240 : 420 = 72
$\snippet{name: long_division, x: 30240, y: 420}$
 
7009 * 24 = 168216
$\snippet{name: column_multiplication, x: 7009, y: 24}$
 
5060 * 73 = 369380
$\snippet{name: column_multiplication, x: 506, y: 73}$
 
1000 − 100 : 5 * (2 + 8) = 1000 − 100 : 5 * 10 = 1000 − 20 * 10 = 1000 − 200 = 800
 
1000 − (100 : 5 * 2 + 8) = 1000 − (20 * 2 + 8) = 1000 − (40 + 8) = 1000 − 48 = 952