1. 8-6 Digit and Coin Problems Steve Blaylock Lakota Schools 2009-2010

2. A pattern we should know… Any two digit number can be expressed as 10x + y – Example 1: 53 can be written as 10(5) + 3 – Example 2: 29 can be written as 10(2) + 9 If we reverse the digits, the new number is 10y + x – Example 1a: The reverse of 53 can be written as 10(3) + 5 – Example 2a: The reverse of 29 can be written as 10(9) + 2

3. The sum of the digits of a two-digit number is 14. If the digits are reversed, the number is 36 greater than the original number. Find the original number. x = tens digitDefine your variables Y = ones digit “The sum of the digits is 14” x + y = 14 “If the digits are reversed, the number is 36 greater than the original number ” 10y + x = 36 + 10x + y

4. The sum of the digits of a two digit number is 12. If the digits are reversed, the new number is 18 less than the original number. Find the original number. x = tens digitDefine your variables Y = ones digit “The sum of the digits is 12” “If the digits are reversed, the number is 18 less than the original number ”

5. Kami has some nickels and some dimes. The value of the coins is $1.65. There are 12 more nickels than there are dimes.How many of each kind of coin does Kami have? n = nickelsDefine your variables d = dimes Number Equation -- “There are 12 more nickels than there are dimes” Value Equation -- “The value of the coins is $1.65” n = d + 12 5n + 10d = 165

6. There were 411 people at a play. Admission was $5 for adults and $3.75 for children. The receipts were $1978.75. How many adults and how many children attended? a = adultsDefine your variables c = children Adult Equation -- Cost Equation --