To order the numbers $2 \frac{1}{2}, \frac{7}{10}, \text{and } 1.39$ from least to greatest, it's helpful to convert all of them to either decimals or fractions.

1. Convert $2 \frac{1}{2}$ (mixed number) to a decimal: $2 \frac{1}{2} = 2 + 0.5 = 2.5$

2. The fraction $\frac{7}{10}$ is already in fractional form, but converting it to a decimal gives: $\frac{7}{10} = 0.7$

3. The number $1.39$ is already in decimal form.

Now we have the following decimals:

• $2.5$
• $0.7$
• $1.39$

To order them from least to greatest: $0.7, 1.39, 2.5$

Thus, the order from least to greatest is: $\frac{7}{10}, 1.39, 2 \frac{1}{2}$

Would you like more details or have any questions?

Here are 5 related questions:

1. How do you convert mixed numbers into decimals?
2. What is the process for comparing fractions with different denominators?
3. Can you explain how to convert decimals into fractions?
4. How do you determine the least common denominator for fractions?
5. What is the difference between rational and irrational numbers?

Tip: Converting all numbers to the same form (decimals or fractions) simplifies comparison.