수와 연산 전체 문제

When we multiplied $47$ times $10,$ the product was $470.$ Notice that $10$ has one zero, and we put one zero after $47$ to get the product. When we multiplied $47$ times $100,$ the product was $4,700.$ Notice that $100$ has two zeros and we put two zeros after $47$ to get the product.

Do you see the pattern? If we multiplied $47$ times $10,000,$ which has four zeros, we would put four zeros after $47$ to get the product $470,000.$

• ⓐ 540
• ⓑ 5,400

• ⓐ 750
• ⓑ 7,500

There are three digits in the factors so there will be $3$ partial products. We do not have to write the $0$ as a placeholder as long as we write each partial product in the correct place.

127,995

653,462

There should be $3$ partial products. The second partial product will be the result of multiplying $896$ by $0.$

Notice that the second partial product of all zeros doesn’t really affect the result. We can place a zero as a placeholder in the tens place and then proceed directly to multiplying by the $2$ in the hundreds place, as shown.

Multiply by $10,$ but insert only one zero as a placeholder in the tens place. Multiply by $200,$ putting the $2$ from the $12.$ $2\cdot 6=12$ in the hundreds place.

$$\begin{array}{c} \\ \\ 896\, \\ \underset{\_\_\_\_\_}{\times 201}\, \\ 896\, \\ \underset{\_\_\_\_\_\_\_\_\_\_}{17920}\, \\ 180,096\,\end{array}$$

365,462

504,108

The word product tells us to multiply. The words of $12$ and $27$ tell us the two factors.

13 · 28; 364

47 · 14; 658

The word twice tells us to multiply by $2.$

2(167); 334

2(258); 516

We are asked to find the total number of stamps.

Write a phrase for the total.	the product of 4 and 20
Translate to math notation.	$4\cdot 20$
Multiply.
Write a sentence to answer the question.	Humberto bought 80 stamps.

Vanessa brought 80 hot dogs.

Erin needs 28 dahlias.

There are 36 women in the choir.

We are asked to find the total number of tiles.