Section C Section C Checkpoint

Problem 1

Draw an array that represents the expression 3×43 \times 4. Explain or show your reasoning.

Show Solution
Solution
Sample responses:
  • Students draw an array with 3 rows and 4 columns.
  • There are 3 rows of 4 dots, so that's 3×43 \times 4 dots.
  • Students draw an array with 3 columns and 4 rows.
  • There are 4 rows of 3 dots, so that's 3×43 \times 4 dots.
Show Sample Response
Sample Response
Sample responses:
  • Students draw an array with 3 rows and 4 columns.
  • There are 3 rows of 4 dots, so that’s 3×43 \times 4 dots.
  • Students draw an array with 3 columns and 4 rows.
  • There are 4 rows of 3 dots, so that’s 3×43 \times 4 dots.

Problem 2

There are 5 rows of chairs in the room. Each row has 7 chairs. How many chairs are there?

  1. Draw an array to represent the situation.
  2. Write an equation to represent the situation. Use a symbol for the unknown.
  3. Solve the problem. Explain or show your reasoning.
Show Solution
Solution
  1. Students draw a 5 by 7 array or 7 by 5 array.
  2. 5×7=?5 \times 7 = {?} or 7×5=?7 \times 5 = {?}
  3. 35 chairs. Sample response:
    7+7=1414+14=2828+7=35\begin{array}{l} 7 + 7 = 14\\ 14 + 14 = 28 \\ 28+7=35\end{array}
Show Sample Response
Sample Response
  1. Students draw a 5 by 7 array or 7 by 5 array.
  2. 5×7=?5 \times 7 = {?} or 7×5=?7 \times 5 = {?}
  3. 35 chairs. Sample response:
    7+7=1414+14=2828+7=35\begin{array}{l} 7 + 7 = 14\\ 14 + 14 = 28 \\ 28+7=35\end{array}