Question

using your math

1. maggie buys 0.4 pounds of rice and claims that she has bought two - fifths of a pound. explain why maggie is correct.
2. a square measures one kilometer by one kilometer. given that one kilometer is equal to 1,000 meters, what is the area of this square in square meters? justify.

1 km = 1,000 m
reviewing your math

1. find each of the following.

(a) 437×25
(b) 15183÷63
(c) $\frac{4}{9}div\frac{10}{3}$ (simplest form)

1. find the following in simplest form: $(\frac{5}{4}+\frac{1}{2})\times(\frac{3}{2}-\frac{1}{6})$. show your work.

Explanation:

4.

Step1: Convert fraction to decimal

To check Maggie's claim, convert $\frac{2}{5}$ to decimal. We know that $\frac{2}{5}=2\div5$.
$2\div5 = 0.4$
Since $0.4$ (the amount of rice she bought in decimal - form) is equal to $\frac{2}{5}$ (in fraction - form), Maggie is correct.

Step1: Recall the area formula for a square

The area formula for a square is $A = s^2$, where $s$ is the side - length of the square. Here, $s = 1$ km. Since $1$ km=$1000$ m, the side - length of the square in meters is $s = 1000$ m.

Step2: Calculate the area in square meters

Substitute $s = 1000$ m into the area formula $A=s^2$. So $A=(1000)^2=1000\times1000 = 1000000$ square meters.

Step1: Multiply the numbers

$437\times25=(400 + 30+7)\times25=400\times25+30\times25 + 7\times25=10000+750 + 175=10925$

Answer:

Maggie is correct because $\frac{2}{5}=2\div5 = 0.4$ pounds.

5.