Exercise 35 Page 18

We are asked to determine by how many times the cost each item has increased from 1960 to 2010.

Item	1960 Cost	2010 Cost
Movie Ticket	$0.75	$9.75
Regular Popcorn	$0.25	$4.10
Regular Drink	$0.35	$3.08

To do so, we need to divide the cost in 2010 of each item by its cost in 1960.

Item	1960 Cost	2010 Cost	(2010 Cost) ÷ (1960 Cost)
Movie Ticket	$ 0.75	$ 9.75	9.75÷ 0.75
Regular Popcorn	$ 0.25	$ 4.10	4.10÷ 0.25
Regular Drink	$ 0.35	$ 3.08	3.08 ÷ 0.35

Let's start with the movie ticket.

Movie Ticket

We will divide the cost of a movie ticket in 2010 by the cost of a movie ticket in 1960. 9.75÷ 0.75 First, let's multiply both the divisor and the dividend by 100. This will make the divisor a whole number. (9.75* 100)÷(0.75 * 100) ⇕ 975÷ 75 Next, before we perform the division, we will first make an estimation. The number 975 is close to 1000 and the number 75 is close to 100. This means that we can make the following estimation.

1000 ÷ 100=10 We found that 975 divided by 75 is about 10. We can calculate the actual quotient by following four steps.

1. Divide
2. Multiply
3. Subtract
4. Compare

As we go, we will bring down the next digit and repeat the steps as needed until the remaining number is zero.

We found that 975 ÷ 75 is equal to 13, which means that 9.75 ÷ 0.75 is also equal to 13. Therefore, a movie ticket costs 13 times as much in 2010 as it did in 1960. Let's write this down! &Movie Ticket: 13 &Regular Popcorn:? &Regular Drink:? We know that this result is reasonable because it is close to our estimation. Now let's find a similar quotient for the prices of a regular popcorn.

Regular Popcorn

This time we will divide the cost of a regular popcorn in 2010 by its cost in 1960. 4.10 ÷ 0.25 Let's multiply the the divisor and dividend by 100 to make them whole numbers. (4.10* 100) ÷ (0.25* 100) ⇕ 410÷ 25 As we did before, we will start by making an estimation. The number 410 is close to 400, so we can make the following estimation. 400÷ 25=16 We found that our result should be about 16. Now, let's divide 410 by 25.

We found that a regular popcorn costs 16.4 times as much in 2010 as it did in 1960. Let's write this down! &Movie Ticket:13 &Regular Popcorn: 16.4 &Regular Drink:? Finally, we will find a similar quotient for a regular drink.

Regular Drink

Let's divide the cost of a regular drink in 2010 by its 1960 cost. 3.08 ÷ 0.35 Just like before, we will make the divisor and the dividend whole numbers by multiplying them by 100. (3.08* 100) ÷ (0.35* 100) ⇕ 308 ÷ 35 Let's estimate the result! The number 308 is close to 300 and the number 35 is close to 30. Therefore, we can make the following estimate. 300÷ 30=10 We found that our result should be about 10. Next, we will divide 308 by 35.

We found that a regular drink costs 8.8 times as much in 2010 as in 1960. &Movie Ticket:13 &Regular Popcorn:16.4 &Regular Drink: 8.8 We found all the required information!