Compare+Difference+Unknown

__**Compare Difference Unknown**__

Connie has 13 marbles. Juan has 5 marbles. How many more marbles does Connie have than Juan?

media type="file" key="Direct Modeling CDU.mov" width="300" height="300"
 * Direct Modeling - students will match items in a one-to-one correspondence between sets until one set is exhausted. This shows the difference the student is looking for (see example on page 17).**
 * = Connie ||= Juan ||
 * = x ||= x ||
 * = x ||= x ||
 * = x ||= x ||
 * = x ||= x ||
 * = x ||= x ||
 * = x ||=  ||
 * = x ||=  ||
 * = x ||=  ||
 * = x ||=  ||
 * = x ||=  ||
 * = x ||=  ||
 * = x ||=  ||
 * = x ||=  ||


 * Modeling -students will match items in a one-to-one correspondence between sets until one is exhausted again, but will not follow the exact order of the numbers appearing in the problem.**

5+ unknown amount = 13

5 +1 +1 +1 +1 +1 +1 +1 +1=13

**Counting (Children's Mathematics Cognitive Guided Instruction pg.18) Students begin with the known and count down or up in order to arrive at the unknown number.**

13-5= ? 13 count back to 5 (13, 12, 11, 10, 9, 8, 7, 6, 5) to find the unknown difference of 8

5+?= 13 5 coun t up to 13 (5, 6, 7, 8, 9, 10, 11, 12, 13) to find the unknown difference of 8 media type="file" key="Counting CDU.mov"


 * Number Facts **
 * (Children's Mathematics Cognitive Guided Instruction pg.24)**

Students work to build a group of "friendly numbers" that help them solve for the "unknown". In this case, the student starts with a total of 13, subtracts 3 (of the 5) to get to 10, and then subtracts the final 2 (of the 5). This leaves them with 8 - the unknown. (ex: 13-3 >10-2=8)

media type="file" key="Math Facts CDU.mov"