There are many opportunities to use 'four-digit PIN numbers' in our daily lives, such as credit card PIN numbers, smartphone passcodes, and PC unlock codes. In all cases, we should use four-digit ...

Much of the United States had rotary-dial telephones long before Victoria. Southwestern Bell’s largest manual exchange telephone district in Texas did not begin to have dial service until 1954, about ...

Four-digit numbers can be partitioned into ones, tens, hundreds and thousands. Understanding the value of each digit makes it easier to compare numbers using the less than (<), greater than (>) and ...