Carroll diagrams are a favourite with the SAT paper writers and it is no surprise to find one in the 2010 SAT paper 1. There is nothing tricky about this and the best approach is to take each number in turn, look at its properties and decide where it should go.
Look at 25. Is it odd? Yes, so it must go in the first column. Is it a 3-digit number or not a 3-digit number? It is a 2-digit number so it will go in the second row. Continue with the other numbers in turn.
Two marks are given for a completely correct answer and one mark can be gained if only one number is placed incorrectly, or is missing.
For question 11 I would recommend writing this out as a multiplication in the standard way. Watch out for children who forget to write the answer in the box after completing the calculation, although they should still be awarded the mark, if the marker follows the guidelines.
- © 2009 Maths Blog