To solve this problem, we need to convert a measurement from millimeters (mm) and centimeters (cm) into inches, and then express that decimal value as a fraction.
Step 1: Understand the Conversion Factor
The standard conversion between metric units and inches is:
$$1 \text{ inch} = 25.4 \text{ millimeters}$$
$$1 \text{ inch} = 2.54 \text{ centimeters}$$
Step 2: Convert Millimeters/Centimeters to Decimal Inches
The image shows an input of
10 mm, which is equal to
1 cm. Let's calculate how many inches that is using the formula:
$$\text{Inches} = \frac{\text{Millimeters}}{25.4}$$
Substitute 10 for millimeters:
$$\text{Inches} = \frac{10}{25.4}$$
$$\text{Inches} \approx 0.3937$$
Rounding to two decimal places, we get
0.39 inches. This matches the "Inch" box in the image.
Step 3: Convert Decimal Inches to a Fraction
Now we need to turn $0.39$ inches into a fraction. Looking at the ruler in the image, the markings are in fractions like $1/8$, $1/4$, etc. The text below the boxes says "$10 \text{ MM} = 1 \text{ CM} = 0.39 \text{ inches} = 3/8''$". Let's verify if $3/8$ is the correct fraction.
Convert the fraction $3/8$ into a decimal to see if it matches our calculation:
$$3 \div 8 = 0.375$$
Let's check the next common fraction size, $13/32$ or $7/16$:
$$7 \div 16 = 0.4375$$
$0.375$ ($3/8$) is very close to $0.39$. In many practical measuring contexts (like construction or woodworking shown on the ruler), measurements are rounded to the nearest standard fraction mark. Since $0.39$ is closest to $0.375$ among the simple eighths,
3/8 is the intended answer shown in the example.
Conclusion:
The task demonstrates that 10 millimeters converts to approximately 0.39 inches, which corresponds to the
3/8 inch mark on the ruler.
Final Answer:
3/8"
Parent Tip: Review the logic above to help your child master the concept of printable mm to inches ruler.
