Challenge 3

Derek: He has an understanding of addition and subtraction, that adding numbers makes a bigger number and you count up and that subtracting numbers makes a smaller number and you count down. However, he has trouble because he tries to do the math in his head or on his fingers but he seems to have trouble sometimes when he reaches 10 since he can't count any more fingers.

Elizabeth: She says that she guesses to get the answer and cannot explain how or why she came up with the number that she did. She understands number concepts and sequences but she tries to do the math in her head and gets a different answer once she is asked to explain it and tries to count it out on her fingers. She can do subtraction with the cows in front of her, but with small numbers (5-2).

Jim: He somewhat understands the concept of adding and subtracting but cannot perform the operations with numbers that are higher than 6 because it becomes too difficult and he guesses answers.

Lauren: She adds by starting with the first number and counting the dots on the dominos until she arrives at her answer. For subtraction, she counts backwards in her head when she can see the manipulatives in front of her but uses her fingers to count down/backwards when trying to solve and understand the word problem about the boys with the candy.