Question

b. use priya’s method to calculate (1.05) • (2.8). you can use the fact that 105 • 28 = 2,940. c. use priya’s method to calculate (0.0015) • (0.024).

Explanation:

Step1: Analyze Priya's method (scaling up and down)

From part b, \(105\times28 = 2940\), and \((1.05)\times(2.8)\) can be seen as scaling \(105\) down by \(100\) (to \(1.05\)) and \(28\) down by \(10\) (to \(2.8\)), so the product scales down by \(100\times10 = 1000\), giving \(2940\div1000 = 2.94\). For \((0.0015)\times(0.024)\), we can scale up \(0.0015\) to \(15\) (multiply by \(10000\)) and \(0.024\) to \(24\) (multiply by \(1000\)).

Step2: Calculate the product of scaled numbers

First, calculate \(15\times24\). \(15\times24=360\).

Step3: Scale the product back down

We scaled up \(0.0015\) by \(10000\) and \(0.024\) by \(1000\), so the total scaling factor is \(10000\times1000 = 10000000\). Now we scale the product \(360\) down by \(10000000\), which is equivalent to dividing by \(10000000\). So \(360\div10000000 = 0.000036\).

Answer:

\(0.000036\)