# 2.4: Estimate Decimal Products and Quotients Using Leading Digits

Difficulty Level: At Grade Created by: CK-12
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Practice Small Decimal Rounding to a Leading Digit

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Have you ever had to figure out a dilemma involving money? Take a look at this situation.

### Vocabulary

Dividend
the number being divided in a division problem. It is often the first number in a problem written horizontally.
Divisor
the number doing the dividing in a division problem.
Estimate
an approximate answer that is reasonable and makes sense for the problem.
the first digits in a decimal-often the whole number part of the decimal.

### Guided Practice

Here is one for you to try on your own.

120.0045÷6.237\begin{align*}120.0045 \div 6.237\end{align*}

Solution

First, we take only the leading digits and rewrite this problem.

120÷6\begin{align*}120 \div 6\end{align*}

Now our work is quite simple.

120÷6=2\begin{align*}120 \div 6 = 2\end{align*}

Our estimate is 2\begin{align*}2\end{align*}.

### Practice

Directions: Estimate each product or quotient by using leading digits.

1. 35.0012÷5.678\begin{align*}35.0012 \div 5.678\end{align*}

2. 5.123×11.0023\begin{align*}5.123 \times 11.0023\end{align*}

3. 12.0034÷4.0012\begin{align*}12.0034 \div 4.0012\end{align*}

4. 12.123×3.0045\begin{align*}12.123 \times 3.0045\end{align*}

5. 48.0012÷12.098\begin{align*}48.0012 \div 12.098\end{align*}

6. 13.012×3.456\begin{align*}13.012 \times 3.456\end{align*}

7. 33.234÷11.125\begin{align*}33.234 \div 11.125\end{align*}

8. 12.098×2.987\begin{align*}12.098 \times 2.987\end{align*}

9. 4.769×8.997\begin{align*}4.769 \times 8.997\end{align*}

10. 14.98÷7.002\begin{align*}14.98 \div 7.002\end{align*}

11. 24.56087÷8.0012\begin{align*}24.56087 \div 8.0012\end{align*}

12. 45.098÷5.0098\begin{align*}45.098 \div 5.0098\end{align*}

13. 9.0987×9.0001\begin{align*}9.0987 \times 9.0001\end{align*}

14. 34.021×4.012\begin{align*}34.021 \times 4.012\end{align*}

15. 21.0098×2.0987\begin{align*}21.0098 \times 2.0987\end{align*}

16. 14.231×3.7601\begin{align*}14.231 \times 3.7601\end{align*}

17. 144.0056÷12.0112\begin{align*}144.0056 \div 12.0112\end{align*}

### Notes/Highlights Having trouble? Report an issue.

Color Highlighted Text Notes

### Vocabulary Language: English

TermDefinition
Dividend In a division problem, the dividend is the number or expression that is being divided.
divisor In a division problem, the divisor is the number or expression that is being divided into the dividend. For example: In the expression $152 \div 6$, 6 is the divisor and 152 is the dividend.
Estimate To estimate is to find an approximate answer that is reasonable or makes sense given the problem.
Leading Digit The leading digit of a decimal number less than one is the first digit to the right of the decimal point that is not a zero.

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