Question

kevin is working with a group of community volunteers to replace rotting boards over the river walkway. they need to replace 7 boards that are each 3/4 feet long. how many total feet of board will they need for the job? This is a multiplication problem, because we have 7 sets of the same item. set up the multiplication expression.

Multiply the numerator of the fraction by the whole number
(7x3)/4= ________/4

Answer 1

To find the total length of the boards needed, you can set up the multiplication expression as follows:

\[
7 \times \frac{3}{4}
\]

To carry out the multiplication, you multiply the numerator (3) by the whole number (7):

\[
\text{Numerator: } 7 \times 3 = 21
\]

Now, you keep the denominator (4) the same, so you write:

\[
\frac{21}{4}
\]

Therefore, the multiplication expression is:

\[
\frac{21}{4} \text{ feet of board}
\]

To express this in mixed number form, you can divide 21 by 4, which gives you:

\[
21 \div 4 = 5 \text{ R } 1
\]

Thus,

\[
\frac{21}{4} = 5 \frac{1}{4}
\]

In conclusion, Kevin and the volunteers will need \( \frac{21}{4} \) feet or 5 \( \frac{1}{4} \) feet of board for the job.