**Predict:** I predict this problem will involve a accessing prior knowledge of these problem solving sums.

**Read: ****In the addition problem shown, the letters A,B and C stand for different digits. What number does ABC represent?**

** ****A B C **

** + A B**

** + A**

** **** 800 **

**Clarify: ****I have no sentences words or phrases to clarify****.**

**Big Question: ****What does ABC equal?**

**Mathematicians Toolbox: ****Use Prior knowledge****.**

**Solve: ****In problems like this before I have used work backwards. So, we start from the column with CBA, which has to equal something with a zero at the end. So what 3 numbers equal 10? the A has to be 7 because the answer is 800 and a is in the first column, and when we carry we want it to equal 8. so, next we figure out what b I and b has to be able to add up with one and seven to make ten in the next column. So b equals . 2 plus 7 equals 9 so c is 1. To make sure we are correct we do the sum again. 721 + 72 + 7 equals 800!**

**Summary: ****I did use my Mathematicians toolbox strategy as well as my prediction in this problem.**