remove extra space between grid components

Question

I am trying to make a calculator app and i used grid for the buttons but when i do that by default there are some margins around the buttons even though i didn't specify one.

yellow part is the grid layout.

Now i tried this method given here. This doesn't seem to work, anyone?

P.s: i am new to android.

Code

 <GridLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="#ff0000"
            android:columnCount="3"

            android:rowCount="5"
            android:layout_weight="1"
            android:useDefaultMargins="false"
            android:alignmentMode="alignMargins"
            android:rowOrderPreserved="false"
            tools:layout_editor_absoluteX="8dp"
            tools:layout_editor_absoluteY="8dp">

            <Button
                android:id="@+id/button4"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_column="0"
                android:layout_columnWeight="1"
                android:layout_row="0"
                android:layout_rowWeight="1"
                android:text="Button"

                tools:layout_editor_absoluteX="136dp"
                tools:layout_editor_absoluteY="100dp" />

            <Button
                android:id="@+id/button5"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_column="1"
                android:layout_columnWeight="1"
                android:layout_row="0"
                android:layout_rowWeight="1"
                android:text="Button"
                tools:layout_editor_absoluteX="116dp"
                tools:layout_editor_absoluteY="289dp" />


            <Button
                android:id="@+id/button6"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_column="2"
                android:layout_columnWeight="1"
                android:layout_row="0"
                android:layout_rowWeight="1"
                android:text="Button"
                tools:layout_editor_absoluteX="129dp"
                tools:layout_editor_absoluteY="255dp" />


            <Button
                android:id="@+id/button8"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_column="0"
                android:layout_columnWeight="1"
                android:layout_row="1"
                android:layout_rowWeight="1"
                android:text="Button"
                tools:layout_editor_absoluteX="64dp"
                tools:layout_editor_absoluteY="259dp" />


            <Button
                android:id="@+id/button9"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_column="1"
                android:layout_columnWeight="1"
                android:layout_row="1"
                android:layout_rowWeight="1"
                android:text="Button" />

            <Button
                android:id="@+id/button10"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_column="2"
                android:layout_columnWeight="1"
                android:layout_row="1"
                android:layout_rowWeight="1"
                android:text="Button"
                tools:layout_editor_absoluteX="129dp"
                tools:layout_editor_absoluteY="217dp" />


            <Button
                android:id="@+id/button12"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_column="0"
                android:layout_columnWeight="1"
                android:layout_row="2"
                android:layout_rowWeight="1"
                android:text="Button" />

            <Button
                android:id="@+id/button13"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_column="1"
                android:layout_columnWeight="1"
                android:layout_row="2"
                android:layout_rowWeight="1"
                android:text="Button" />

            <Button
                android:id="@+id/button14"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_column="2"
                android:layout_columnWeight="1"
                android:layout_row="2"
                android:layout_rowWeight="1"
                android:text="Button" />


            <Button
                android:id="@+id/button16"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_column="0"
                android:layout_columnWeight="1"
                android:layout_row="3"
                android:layout_rowWeight="1"
                android:text="Button" />


            <Button
                android:id="@+id/button17"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_column="1"
                android:layout_columnWeight="1"
                android:layout_row="3"
                android:layout_rowWeight="1"
                android:text="Button" />

            <Button
                android:id="@+id/button18"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_column="2"
                android:layout_columnWeight="1"
                android:layout_row="3"
                android:layout_rowWeight="1"
                android:text="Button" />


            <Button
                android:id="@+id/button20"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_column="0"
                android:layout_columnWeight="1"
                android:layout_row="4"
                android:layout_rowWeight="1"
                android:text="Button" />

            <Button
                android:id="@+id/button21"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_column="1"
                android:layout_columnWeight="1"
                android:layout_row="4"
                android:layout_rowWeight="1"
                android:text="Button" />

            <Button
                android:id="@+id/button22"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_column="2"
                android:layout_columnWeight="1"
                android:layout_row="4"
                android:layout_rowWeight="1"
                android:text="Button" />

        </GridLayout>