Question

length lab

1. what does each unit represent?

(a) mm =
(c) cm =
(b) m =
(d) km =

1. how much does each one equal?

(a) 1 m =
cm
(b) 1 cm =
mm
(c) 1 km =
m

1. which measurement is the largest? circle your answer for each pair.

(a) 14 mm or 1 cm
(b) 334 m or 1 km
(c) 1 m or 990 cm
(d) 145 m or 145 km
(e) 3.4 cm or 30 mm
(f) 10 km or 1000 cm

1. use a metric ruler or meter stick to find each measurement.

(a) length of the line in centimeters
(b) length of the line to the nearest centimeter
(c) height of the rectangle to the nearest millimeter
(d) width of the rectangle to the nearest millimeter
radius of the circle to the nearest millimeter
diameter of the circle in centimeters
diameter of the circle to the nearest centimeter

Explanation:

Step1: Recall metric - length unit definitions

(a) $mm$ (millimeter) is one - thousandth of a meter. (b) $m$ (meter) is the base unit of length in the metric system. (c) $cm$ (centimeter) is one - hundredth of a meter. (d) $km$ (kilometer) is one thousand meters.

Step2: Recall metric - length unit conversions

(a) Since $1m = 100cm$. (b) Since $1cm=10mm$. (c) Since $1km = 1000m$.

Step3: Compare measurements

(a) Convert $1cm$ to $mm$: $1cm = 10mm$, so $14mm>1cm$. (b) Convert $1km$ to $m$: $1km = 1000m$, so $1km>334m$. (c) Convert $1m$ to $cm$: $1m = 100cm$, so $990cm>1m$. (d) Convert $145km$ to $m$: $145km=145\times1000m = 145000m$, so $145km>145m$. (e) Convert $3.4cm$ to $mm$: $3.4cm=3.4\times10mm = 34mm$, so $3.4cm>30mm$. (f) Convert $10km$ to $cm$: $10km = 10\times1000\times100cm=1000000cm$, so $10km>1000cm$.

Step4: Use a ruler for actual measurements (can't be done here as no actual ruler - based measurements)

(a) Without a ruler, we can't give the length of the line in centimeters. (b) Without a ruler, we can't give the length of the line to the nearest centimeter. (c) Without a ruler, we can't give the height of the rectangle to the nearest millimeter. (d) Without a ruler, we can't give the width of the rectangle to the nearest millimeter. (e) Without a ruler, we can't give the radius of the circle to the nearest millimeter. (f) Without a ruler, we can't give the diameter of the circle in centimeters. (g) Without a ruler, we can't give the diameter of the circle to the nearest centimeter.

Answer:

1. (a) One - thousandth of a meter; (b) Base unit of length in the metric system; (c) One - hundredth of a meter; (d) One thousand meters.
2. (a) 100; (b) 10; (c) 1000.
3. (a) 14 mm; (b) 1 km; (c) 990 cm; (d) 145 km; (e) 3.4 cm; (f) 10 km.
4. Measurements can't be provided without a metric ruler or meter - stick.