Understand Problem: Understand the problem and write down the multiplication expression. We need to multiply 0.4 by 8000. The expression is 0.4 * 8000. Multiply Decimal by Whole Number: Multiply the decimal number by the whole number. To multiply 0.4 by 8000, we can use the property that multiplying by a power of 10 simply shifts the decimal point to the right. Since 8000 is 8 × 1000, we can multiply 0.4 by 8 first and then by 1000. Multiply 0.4 by 8: Multiply 0.4 by 8. 0.4 * 8 = 3.2. This is because 4 times 8 is 32, and since there is one decimal place in 0.4, we place the decimal point one digit from the right in the result. Multiply Result by 1000: Multiply the result by 1000. Now, we multiply 3.2 by 1000. To do this, we move the decimal point three places to the right, because multiplying by 1000 is equivalent to shifting the decimal point three places to the right. Calculate Final Result: Calculate the final result. 3.2 * 1000 = 3200. We have moved the decimal point three places to the right, so the final answer is 3200.

Grade 6

Multiply whole numbers

Full solution

Q. Multiply:

\newline

0.4 \times 8000

Understand Problem: Understand the problem and write down the multiplication expression. $\newline$ We need to multiply $0.4$ by $8000$ . The expression is $0.4 \times 8000$ .
Multiply Decimal by Whole Number: Multiply the decimal number by the whole number. $\newline$ To multiply $0.4$ by $8000$ , we can use the property that multiplying by a power of $10$ simply shifts the decimal point to the right. Since $8000$ is $8 \times 1000$ , we can multiply $0.4$ by $8$ first and then by $1000$ .
Multiply $0$ . $4$ by $8$ : Multiply $0.4$ by $8$ . $\newline$ $0.4 \times 8 = 3.2$ . This is because $4$ times $8$ is $32$ , and since there is one decimal place in $0.4$ , we place the decimal point one digit from the right in the result.
Multiply Result by $1000$ : Multiply the result by $1000$ . Now, we multiply $3.2$ by $1000$ . To do this, we move the decimal point three places to the right, because multiplying by $1000$ is equivalent to shifting the decimal point three places to the right.
Calculate Final Result: Calculate the final result. $\newline$ $3.2 \times 1000 = 3200$ . We have moved the decimal point three places to the right, so the final answer is $3200$ .