Use the hundreds grid to answer the question?

Give the decimal multiplication equation shown by the model. Explain how each part of the equation is shown on the model . Include the final product.

1 answer

To help you with the question regarding a hundreds grid or a model that represents decimal multiplication, let's consider a common example where we multiply two decimals: for instance, \(0.3\) (or \(3/10\)) and \(0.4\) (or \(4/10\)).

Decimal Multiplication Equation:

The multiplication equation for the example would be: \[ 0.3 \times 0.4 \]

Explanation of Each Part with the Model:

  1. Hundreds Grid Representation:

    • A hundreds grid is typically a square grid with 10 rows and 10 columns, totaling 100 small squares, where each square represents \(0.01\) (or 1 hundredth).
  2. Representing \(0.3\):

    • To represent \(0.3\) on the hundreds grid, we shade in 3 rows (30 squares out of 100). This shows that \(0.3\) represents 30 hundredths. In the grid, you could visualize this as covering 30 out of the 100 total squares.
  3. Representing \(0.4\):

    • For \(0.4\), you would shade in 4 columns on the grid (40 squares out of 100). This indicates that \(0.4\) represents 40 hundredths. You can visualize this as covering 40 squares out of the total 100.
  4. Finding the Overlap for the Product:

    • To find the product \(0.3 \times 0.4\), you would look for the area where the rows representing \(0.3\) overlap with the columns representing \(0.4\).
    • Typically, for a grid divided into tenths, you would find that \(0.3\) (30 hundredths) and \(0.4\) (40 hundredths) produce a shaded area that represents \(0.12\) (or \(12\) hundredths) because \(30\) multiplied by \(40\) gives \(1200\) when considering it as \(1200\) hundredths of \(10000\).

Final Product:

The final product of \(0.3 \times 0.4\) is: \[ 0.12 \]

In conclusion, using a hundreds grid, the described model allows us to visually illustrate the multiplication of \(0.3\) and \(0.4\) leading to a final product of \(0.12\).