Multiply numbers up to 4 digits by a one- or two-digit number using a formal written method, including long multiplication for two-digit numbers

What this means, in plain words

A columnar method is the written layout where digits are lined up in their place value columns and worked one column at a time.

A digit is one of the ten symbols, 0 to 9, that all numbers are written with.

Multiplication is repeated addition of equal groups. Division shares a total into equal groups, or works out how many groups fit.