Grids – Cardinal Directions
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00:00Hi kids, today we will learn about grids and cardinal directions.
00:08So let's get started.
00:12Here is a grid.
00:15The horizontal partitions in the grid are called its rows and vertical partitions in
00:22grids are called columns.
00:26We can give names to rows and columns, like here.
00:32Alphabets A to G are assigned to columns and numbers 1 to 8 are assigned to rows.
00:42Each individual partition in the grid is a cell and we assign unique names to each cell
00:50by joining its row name and column name.
00:55Example, name of this particular cell is B4, as its column name is B and row name is 4.
01:06And this cell is D5, as its column name is D and row name is 5, so it's D5.
01:19Similarly, this cell is G3, as its column name is G and row name is 3, so it's G3.
01:29Now let's learn about cardinal directions.
01:33If we move upwards, we say we are moving in north direction.
01:39If we move downwards, we say we are moving in south direction.
01:45If we move toward right, we say we are moving in east direction.
01:51If we move toward left, we say we are moving in west direction.
01:57Here, Joy is standing at a position.
02:02Can you name its position?
02:05Joy is standing at row 1 and column A, so he is standing at A1.
02:13Now, Joy has to reach the help bottle, which is at position E4, that is in column E and row 4.
02:25Now, let's see how Joy can reach position E4.
02:31First, Joy will move 4 steps towards east or right, and then move 3 steps towards south.
02:40And, Joy will reach the help bottle.
02:44Now, help bottle gave Joy a hint.
02:48That is a hint to the key of treasure, which is F2.
02:55Now, let's reach F2.
03:00If Joy moves 1 step right or east, and then 2 steps north, we reach F2.
03:08Yeah, we got the key here.
03:11Now, next hint on the key is C5.
03:16Let's reach C5.
03:19For this, we have to move 3 steps west or left, and then 3 steps south.
03:27Yeah, we got the treasure here.
03:30So kids, now we know how we can move in a grid to any desired location.
03:38So, we learned naming in a grid and cardinal directions.
03:43Now, let's learn more on grids.
03:47We will learn calculating area and perimeter in grids.
03:53Here we have a map of university.
03:57Yellow area shows the science department.
04:01Brown area shows the history department.
04:05Blue area shows the math department.
04:09Black area is the entrance gate of university.
04:15Red area shows canteen areas.
04:19Pink area shows the English department.
04:23Gray area shows the roads.
04:27Green area shows the garden area.
04:31Now, let's answer a few questions.
04:34Which part of the university has the greatest area?
04:39Garden area is covering the greatest area.
04:44Which part of university has the least area shown in map?
04:50Entrance gate is covering the least area of map.
04:56If each cell is 4 meters square, what is the area of English department?
05:04Let's find it out.
05:07English department is the area in pink.
05:11Pink area spans 4 rows of 4 squares each.
05:17So, 4 multiplied by 4 equals 16 squares.
05:22And, 1 square equals 4 meters square.
05:28So, 16 square equals 4 multiplied by 16 equals 64.
05:37So, area of English department equals 64 meters square.
05:44Now, what is the total area covered by all the canteens,
05:51given that each cell is 4 meters square?
05:55Let's find it out.
05:58There are 4 canteen areas.
06:01And, each canteen spans 4 small squares.
06:06So, 4 canteens will span 4 multiplied with 4.
06:11That is 16 small squares.
06:15It is same as English department.
06:19So, its area is also 16 multiplied by 4 equals 64 meters square.
06:30Now, let's move on to another question.
06:35Now, if the side of each small square measures 2 centimeters,
06:40then what is the parameter of history department?
06:45Let's calculate the parameter of history department.
06:50We know parameter is the length of boundary of a closed figure.
06:57Length of side of each square is 2 centimeters.
07:03Now, count the number of sides of square
07:06to make up the boundary of history department.
07:10History department spans 5 columns.
07:13So, 5 sides are facing on top and 5 sides are facing on the bottom.
07:21That is 10 sides.
07:24It has 4 rows.
07:27So, 4 sides are facing on left and 4 sides facing on the right.
07:35That is 8 sides.
07:37So, in total, 18 sides are facing on the boundary of history department.
07:45And one side measures 2 centimeters.
07:49So, 18 multiplied by 2 equals 36.
07:56So, 36 centimeters is the parameter of history department.
08:03Now, let's move on to next question.
08:07If a person is standing at the entrance of university,
08:11that is at A8,
08:14what will be the shortest path by road to the math department?
08:19Let's find it out.
08:23Person will move 15 squares east and then 1 square north
08:29and will reach the math department.
08:32So, kids, now you know what are grids,
08:36what are columns and rows,
08:38how to name locations in a grid,
08:41what are cardinal directions,
08:44and also how to find area and parameter in case of simple grids.
08:49Now, you may go ahead and take a quiz to learn more.
08:53Bye-bye.