This question tests 2nd grade understanding of partitioning rectangles into equal squares and counting total (CCSS 2.G.A.2: Partition a rectangle into rows and columns of same-size squares and count to find the total number). A rectangle can be divided into equal squares by drawing rows (horizontal lines) and columns (vertical lines). Rows go across; columns go up and down. All the squares must be the same size. In this problem, the rectangle has 3 rows of 4 squares each. To find the total squares, students can count one-by-one, count by rows (add the number in each row), or multiply rows × columns. Choice A is correct because 4+4+4 shows adding the 4 squares in each of the 3 rows, giving the total of 12 squares. This correctly represents repeated addition for the total squares in the rectangle. Choice C represents adding rows + columns (3+4=7) instead of repeated addition of squares per row. This error typically happens when students confuse the dimensions with the counting method. To help students: Use hands-on materials like square tiles or graph paper. Physically build rectangles with tiles and count together. Teach rows as "going across" and columns as "going up and down". Show counting by rows: count squares in first row (4), recognize each row has same number (4), add rows (4+4+4=12). Connect to repeated addition (4+4+4) and early multiplication (3 rows × 4 per row = 12). Have students color or mark each square as they count to avoid skipping or double-counting. Practice drawing partitions on blank rectangles using ruler for equal squares.

To find the total number of squares in a rectangle grid, multiply the number of columns by the number of rows: 6 × 4 = 24 squares. Choice A incorrectly adds instead of multiplies. Choice B adds the perimeter counts incorrectly. Choice D multiplies correctly but then adds 2 for an unknown reason.

To find squares per row, divide total squares by number of rows: 18 ÷ 3 = 6 squares in each row. Choice A (5) would give only 15 total squares (5 × 3). Choice C (9) would give 27 total squares (9 × 3). Choice D (15) subtracts rows from total instead of dividing.

When you see a problem about arranging objects in rows and columns, you're working with arrays - a way to organize things in equal groups. Think about how seats in a theater or desks in a classroom are arranged in neat rows and columns.

Maria has 15 squares total arranged in 3 columns. To find how many rows she made, you need to figure out how many squares are in each column. Since the squares are arranged equally, each column must have the same number of squares. This is a division problem: $$15 ÷ 3 = 5$$. So there are 5 squares in each column, which means there are 5 rows.

Let's see why the other answers don't work. Choice A suggests 3 rows because "columns equal rows," but this isn't a rule - rectangles can have different numbers of rows and columns. If there were 3 rows and 3 columns, you'd only have $$3 × 3 = 9$$ squares, not 15. Choice B adds 15 + 3 = 18, but addition doesn't help when you need to split squares into equal groups. Choice C subtracts 15 - 3 = 12, but subtraction also doesn't solve this grouping problem.

The correct answer is D because division tells you how many equal groups you can make. When you have a total number of objects arranged in equal rows and columns, divide the total by the number of columns (or rows) to find the other dimension. Remember: multiplication and division work together in array problems - if $$3 × 5 = 15$$, then $$15 ÷ 3 = 5$$.

The original rectangle has 4 × 6 = 24 squares. Removing the middle 2 columns removes 2 × 4 = 8 squares. Remaining squares: 24 - 8 = 16 squares. Choice B (18) removes only 6 squares instead of 8. Choice C (20) removes only 4 squares instead of 8. Choice D (22) removes only 2 squares instead of 8.

To find the number of columns, divide the total squares by the number of rows: 20 ÷ 4 = 5 columns. Choice A assumes rows and columns are always equal, which isn't true. Choice C subtracts rows from total squares incorrectly. Choice D adds rows to total squares, which doesn't give column count.

This question tests 2nd grade understanding of partitioning rectangles into equal squares and counting total (CCSS 2.G.A.2: Partition a rectangle into rows and columns of same-size squares and count to find the total number). A rectangle can be divided into equal squares by drawing rows (horizontal lines) and columns (vertical lines). Rows go across; columns go up and down. All the squares must be the same size. In this problem, there are 3 rows with 4 squares in each. To find the total squares, students can count one-by-one, count by rows (add the number in each row), or multiply rows × columns. Choice D is correct because there are 3 rows with 4 squares in each row, so 4+4+4=12 squares, or 3×4=12 squares, or counting all squares one by one gives 12 total. This correctly counts all the equal squares in the rectangle. Choice A represents adding rows + columns (3+4=7) instead of multiplying (3×4=12). This error typically happens when students use wrong operation. To help students: Use hands-on materials like square tiles or graph paper. Physically build rectangles with tiles and count together. Teach rows as "going across" and columns as "going up and down". Show counting by rows: count squares in first row (4), recognize each row has same number (4), add rows (4+4+4=12). Connect to repeated addition (4+4+4) and early multiplication (3 rows × 4 per row = 12). Have students color or mark each square as they count to avoid skipping or double-counting. Practice drawing partitions on blank rectangles using ruler for equal squares. Watch for: counting grid lines instead of squares, counting corners/intersection points instead of squares, stopping count early, confusing row count with total count, drawing unequal squares (rectangles instead).

This question tests 2nd grade understanding of partitioning rectangles into equal squares and counting total (CCSS 2.G.A.2: Partition a rectangle into rows and columns of same-size squares and count to find the total number). A rectangle can be divided into equal squares by drawing rows (horizontal lines) and columns (vertical lines). Rows go across; columns go up and down. All the squares must be the same size. In this problem, the rectangle has 3 rows of 4 squares each. To find the total squares, students can count one-by-one, count by rows (add the number in each row), or multiply rows × columns. Choice A is correct because 4+4+4 shows adding the 4 squares in each of the 3 rows, giving the total of 12 squares. This correctly represents repeated addition for the total squares in the rectangle. Choice C represents adding rows + columns (3+4=7) instead of repeated addition of squares per row. This error typically happens when students confuse the dimensions with the counting method. To help students: Use hands-on materials like square tiles or graph paper. Physically build rectangles with tiles and count together. Teach rows as "going across" and columns as "going up and down". Show counting by rows: count squares in first row (4), recognize each row has same number (4), add rows (4+4+4=12). Connect to repeated addition (4+4+4) and early multiplication (3 rows × 4 per row = 12). Have students color or mark each square as they count to avoid skipping or double-counting. Practice drawing partitions on blank rectangles using ruler for equal squares.