# Resources tagged with: Reading and writing numbers

### There are 6 results

Broad Topics >

Numbers and the Number System > Reading and writing numbers

##### Age 11 to 14 Challenge Level:

What are the last two digits of 2^(2^2003)?

##### Age 11 to 14 Challenge Level:

What is the last digit of the number 1 / 5^903 ?

##### Age 11 to 14

This article explains how credit card numbers are defined and the check digit serves to verify their accuracy.

##### Age 11 to 14 Challenge Level:

Consider all two digit numbers (10, 11, . . . ,99). In writing down
all these numbers, which digits occur least often, and which occur
most often ? What about three digit numbers, four digit numbers. . . .

##### Age 11 to 14 Challenge Level:

How many positive integers less than or equal to 4000 can be
written down without using the digits 7, 8 or 9?

##### Age 11 to 14 Challenge Level:

How many six digit numbers are there which DO NOT contain a 5?