Justin wants to buy 10 bottles of juice the juice cost 1.15 per bottle he wants to multiply 1.15 by 10 to find the total cost of the bottles of juice which method can he use to find the product of 1.15 and 10.a. He knows that 10 is 10 to the power of 2 so he needs to move the decimal

Question

Point in 1.15 two places to the left b. He knows that 10 is 10 to the power of 1 so he needs to move the decimal
Point I’m 1.15 one place to the left c. He knows that 10 is 10 to the power of 1 so he needs to move the decimal
Point I’m 1.15 one place to the right d. He knows that 10 is 10 to the power of 2 so he needs to move the decimal point in 1.15 two places to the right

Answer 1

To find the product of 1.15 and 10, Justin can multiply 1.15 directly by 10.

However, if we consider the concept of shifting the decimal point as a way to understand multiplication by powers of 10:

• When multiplying by \(10^1\) (which is simply 10), the decimal point in the number is moved one place to the right.

Given the choices: a. He knows that 10 is \(10^2\) so he needs to move the decimal point in 1.15 two places to the left. (Incorrect) b. He knows that 10 is \(10^1\) so he needs to move the decimal point in 1.15 one place to the left. (Incorrect) c. He knows that 10 is \(10^1\) so he needs to move the decimal point in 1.15 one place to the right. (Correct) d. He knows that 10 is \(10^2\) so he needs to move the decimal point in 1.15 two places to the right. (Incorrect)

The correct method is described in option c: He knows that 10 is \(10^1\) so he needs to move the decimal point in 1.15 one place to the right.

Thus, \(1.15 \times 10 = 11.5\).