I use this worksheet in math but it could be used in any subject area. In math, I used it as a beginning activity. Students would write down the problem or whatever was placed on the board. They would then write if they agreed or disagreed with what was on the board. Then they had to explain why they thought the way they did. For example, the problem could have been anything from 5+2=9, 431 is the same as 4 hundreds, 3 tens and 1 one, or we would put something with partitioning, or measurement. Then the students would explain their thinking by agreeing or disagreeing.