Question

7 trey makes 4 groups of books. each group has 9 books. how many books does trey have? select all the equations that model the problem. a ( 9 \times 4 = 36 ) b ( 4 \times 9 = 36 ) c ( 9 + 9 + 9 + 9 = 36 ) d ( 4 + 9 = 13 ) e ( 4 + 4 + 4 + 4 + 4 + 4 + 4 + 4 = 32 ) 8 miroki uses 5 pieces of string to measure the length of a shelf. each string is 9 centimeters long. what multiplication equation can you write to model the problem? what is the length of the shelf? 9 elsie tells reza she arranged bricks for a ( 9 \times 4 ) walkway. how might reza describe the arrangement of bricks in elsie’s rectangular walkway? 10 misha writes 5 storybooks. each storybook has 7 pages. how many pages are in misha’s storybooks? - draw a bar model to show the problem. - write an equation and solve the problem.

Explanation:

Question 7

Step1: Analyze Option A

The problem is about 4 groups with 9 books each. Multiplication \(9\times4\) represents 4 groups of 9, so \(9\times4 = 36\) is correct.

Step2: Analyze Option B

Multiplication is commutative, so \(4\times9\) is the same as \(9\times4\), so \(4\times9 = 36\) is correct.

Step3: Analyze Option C

Adding 9 four times (\(9 + 9+9 + 9\)) is the same as \(9\times4\), so this is correct.

Step4: Analyze Option D

\(4 + 9\) is adding the number of groups and books per group, which is not relevant, so incorrect.

Step5: Analyze Option E

Adding 4 eight times is not related to the problem, so incorrect.

Step1: Determine the multiplication equation

There are 5 strings, each 9 cm long. The multiplication equation is \(5\times9\) (or \(9\times5\)).

Step2: Calculate the length

\(5\times9 = 45\) (or \(9\times5 = 45\)).

In a rectangular arrangement for a \(9\times4\) walkway, Reza could describe it as having 9 bricks in each of 4 rows (or 4 bricks in each of 9 columns), since the multiplication \(9\times4\) can represent 9 units per row and 4 rows (or 4 units per column and 9 columns) in a rectangle.

Answer:

A. \(9\times4 = 36\), B. \(4\times9 = 36\), C. \(9 + 9+9 + 9 = 36\)

Question 8