Question

4 Kalani multiplies 0.05 x 0.8 on a calculator. The calculator shows a product

of 0.04. Kalani says the calculator must be broken because multiplying tenths
by hundredths gives a product in the thousandths. Is Kalani's calculator
broken?

Answer 1

• No

Explanation:

First, let's multiply the last digits of the products.

• => 5 x 8 = 40

We know that:

• The number must have a value in the thousandths.
• The hundredths and the thousandths of the product must have digits 4 and 0.

Now, let's put them together.

• => 0.040 = 0.04

Hence, Kalani's calculator is not broken. It is showing the correct value. To check this, let's multiply the products together in fractions.

Converting (Decimal - Fraction):

• 0.05 = 5/100
• 0.8 = 80/100

Multiplying:

• => 5/100 x 80/100
• => 5/100 x 4/5

Converting (Fraction - Decimal):

• => 4/100 = 0.04
  `(Proved)`