Compare+Quantity+Unknown

Compare Quantity Unknown

Juan has five marbles. Connie has 8 more than Juan. How many marbles does Connie have?

Direct Modeling Strategy Number Sentence: 5+8=? 5+8=13

media type="file" key="Movie on 2010-09-21 at 14.06.mov" width="300" height="300" Written Explanation: Christine makes a set of 5 cubes and adds 8 more to figure out Connie's total. She counted all the cubes together to find total.

Counting Strategy Number Sentence: 5+8=? and 8+5=? 5+8=13 and 8+5=13 media type="file" key="Movie on 2010-09-21 at 14.18

Written Explanation: Christine started with the number 5 in her head and counted 8 more to find the total number of marbles Connie had. She then started with the number 8 and counted 5 more to find the total number of marbles Connie had.

Known Facts Strategy Number Sentence: 5+5=10 and 10+3=13 5+8=13 media type="file" key="Movie on 2010-09-21 at 14.28.mov" width="300" height="300"

Written Explanation: Christine used known number facts. She did not automatically know 5+8 so she used the known facts 5+5=10 and 5+3=8 to know that she could add 10+3 to get to 13, which is the total number of marbles Connie had.