There are 23 classes in the fourth grade. each grade has 21 students. write a number sentence that will provide a reasonable estimate for the number of students in the fourth grade. explain how you found your estimate.

If x is 6, then 7x= a. 13 b. 42 c. 42x d. 76

5. which description does not guarantee that a quadrilateral is a squar ajo is a parallelogram with perpendicular diagonals 0% has all sides congruent and all angles congruent o has all right angles and has all sides congruent 10% is both a rectangle and a rhombus 30%

White shapes and black shapes are used in a game. some of the shapes are circles. while the rest are squares. the ratio of the number of white shapes to the number of black shapes is 5: 11. the ratio of the number of white cicrles to the number of white squares is 3: 7. the ratio of the number of black circles to the number of black squres is 3: 8. work out what fraction of all the shapes are circles.