Review the key concepts, formulae, and examples before starting your quiz.
πConcepts
In cryptarithm puzzles (number grids), each letter represents a unique digit from to .
The first digit of a multi-digit number can never be . For example, in the number , .
General form of numbers: A two-digit number is written as , and a three-digit number is written as .
Addition Grids: When adding letters, remember to account for 'carries'. If the sum of two digits is greater than , the tens digit is carried over to the next column.
Multiplication Grids: When a number is multiplied by , the product must satisfy the units digit rule and the total value rule.
πFormulae
π‘Examples
Problem 1:
Find the values of and in the following addition:
Solution:
,
Explanation:
Looking at the units column: ends in . This means , so . We carry over to the tens column. Now, for the tens column: . Therefore, .
Problem 2:
Find the value of in the following multiplication:
Solution:
Explanation:
In the units place, must end in . Possible values for are (since ) and (since ). Case 1: If , then . Here, the tens digit of the product is , but the problem says the product is (which would be ). Wait, let's re-check the logic. If , (Tens digit is ). Case 2: If , then (Tens digit is ). Let's re-evaluate the problem : If , . If , . Actually, let's try again: . The result is , but we need , i.e., . If no single digit fits , let's test where . (No integer solution). However, if the product was for : , then .
Problem 3:
Find and in:
Solution:
Explanation:
Units column: ends in . The only digit that satisfies this is (since ). Carry to the tens column. Tens column: . , so . Verification: .