Grades 3-4 Video Solutions 2020-2020Grades34prob4

Video Transcription

Problem number four. Which of the following figures has the largest part shaded? Each of the figures is made up of 16 unit squares and has either whole  squares or half squares shaded. One way to solve this problem is to figure out how many squares are unshaded in each figure. These will be easier to count  because there are fewer of them. The figure that has the least unshaded squares will have the largest number of squares shaded, and the largest number of  squares shaded will give us the greatest part shaded. In figure A, there are two whole squares that are unshaded and two half squares. Two halves make a whole, so  in total there are three squares here that are unshaded. In B, there are three whole squares unshaded and one half square. Three plus one half is three and  a half. In figure C, there are two whole squares that are unshaded and one, two, three half squares. So two of the halves make a whole, so we have three and a half  unshaded squares. In figure D, there are one, two, three whole unshaded squares and  one half square. So again, we have three and a half unshaded squares. In E, we only have half squares that are unshaded, and there are one, two, three, four, five, six, seven of  them. One half plus one half plus one half plus one half plus one half plus two more halves, which  gives us one, two, three whole squares and a half. We see that all the figures except A have three and a half unshaded squares and A has only three unshaded squares. Since A  has the least unshaded squares, it has the most shaded squares. So our answer is A.

Video Summary

The problem involves identifying which figure has the largest shaded portion among five figures, each consisting of 16 unit squares. By calculating the unshaded areas, it becomes easier to determine the mostly shaded figure. Figure A has three unshaded squares, while figures B, C, D, and E have three and a half unshaded squares each. Thus, with the least number of unshaded squares, Figure A has the largest shaded area, making it the answer.