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Area (age 8+)

Measure areas by counting unit squares (square cm, square m, square in, square ft)

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What a learner can do afterwards

  • Count unit squares to find the area of an L-shaped figure
  • Measure the area of a book cover using square-centimetre tiles
  • Compare areas of two shapes by counting their unit squares

1 · Read

Area is the amount of flat space inside a shape. To measure it exactly, cover the shape with small squares that are all the same size, called unit squares, then count them. If each square is one centimetre wide, you are counting square centimetres. The same idea works for square metres, square inches, and square feet. If a square is only half inside, count it as about a half.

Tap to fill the grid, one at a time: 3 rows of 4.
Count every square inside this rectangle: 3 rows of 4 squares makes 12 square units.
Try it together

Mia draws an L-shaped figure on centimetre paper. She counts the unit squares inside it one part at a time: 5 squares in the tall part and 3 squares in the short part. 5 plus 3 is 8, so the area of her figure is 8 square centimetres.

You can compare two shapes by counting the unit squares inside each one. Whichever shape has more unit squares has the bigger area, even if the shapes look very different.

Good to know

Sometimes a square is only half inside the shape. Count it as about a half instead of a whole square, then add the halves together for a sensible estimate.

Area is the number of unit squares that fit inside a shape, so count them all and estimate sensibly for any partial squares.

More to read

Area of rectangles review

Area counts the unit squares inside a shape. Cover a rectangle with tiles and count them all: a 5 by 3 rectangle holds exactly 15. Multiplying length times width gives the same total faster: 5 x 3 = 15. Counting teaches what area means and multiplying speeds it up. Trust both and cross check. When count and calculation agree, the answer is solid. When they disagree, recount before recomputing.

How to Find the Area of a Rectangle: Formula & Review

Rectangles obey one tidy rule: area equals length times width. Measure both sides in the same unit, multiply, and label the answer in square units. A book cover 6 tiles long and 4 tiles wide covers 24 square tiles. The formula is only a shortcut for counting. If the numbers feel shaky, sketch the grid and count. Squares counted one by one never lie. Use the shortcut daily and the count to settle doubts.

Tile rectangles with squares to make arrays and relate the side lengths to area

Tiling builds arrays row by row. Three rows of 4 tiles make 12, and the sides read 3 by 4. Side lengths and tile counts lock together: rows times columns always equals the total. L-shapes tile in two chunks. Split the L into rectangles, tile each chunk, then add the counts. An L of 8 plus 4 holds 12. Splitting never changes the total, it only organises the count.

Key ideas: find the area of shapes and represent area data on a line plot

Comparing areas means counting the same unit for both shapes. Shape A with 9 squares beats shape B with 7 squares, whatever their outlines look like. Funny shapes mislead eyes: tall and thin can look bigger than short and wide while holding fewer squares. Count first, judge second. Half squares count too: two halves make one whole. Add full squares plus paired halves and the true order appears.

Explore more

2 · Watch

En anglais

Take it off screen

Print a worksheetA4 with an answer key page for grown-ups. No screen, no internet.

Where it sits

Where this leads

Jobs that lean on this skill. Follow one to see everything it is built on.

Then practise

18 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.

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Area (age 8+) · Mathematics, ages 8 to 9 · LightMySky