**Problem Solving 34**

Our four step

For multi-step problems you will need to work through this process more than once.

Keywords / information: how much altogether, $5, $20, $15, $10, $20

Irrelevant information: birthday is on Friday, turning eleven, Aunty Anne lives overseas.

We have five different dollar amounts and need to know how much money there is altogether, so we need to add.

Since we know we need to add, we can work out our algorithm and calculate the answer: 5 + 20 + 15 + 10 + 20 = 70

Our answer is $70 (don't forget the dollar sign).

We were asked to add five different dollar figures each of which was $20 or less. Our total figure needs to be:

1. more than each of the individual dollar amounts - which it is.

2. less than $100 (as each figure was $20 or less and 5 x $20 = $100) - which it is.

We can conclude that our answer makes sense.

If it didn't make sense we would work through the

Keywords / information: how much change, $10, $3.20

Irrelevant information: the boy's name is Tom, his dad gave him the money

There is $10 and we need to know how much money is left after spending some, so we need to subtract.

Since we know we need to subtract, we can work out our algorithm: $10 - $3.20 = $6.80

Our answer is $6.80 (don't forget the dollar sign).

We needed to subtract $3.20 from $10. If we round $3.20 to $3, we know our change will be close to $7 because 3 and 7 are

If it didn't make sense we would work through the

**ROCS**approach:**ead - the question carefully. Underline keywords / information and ignore any irrelevant (unimportant) information.****R****peration - what operation do you need to solve the problem? Do you need to add, subtract, multiply or divide?****O****alculate the answer.****C****ense - does your answer make sense? If it does, you're probably correct. If not, work through the process again.****S**For multi-step problems you will need to work through this process more than once.

**Word Problem 1***It is Argent's birthday on Friday. He is turning eleven. His aunts and uncles have decided to give him money. So far Argent has received $5, $20, $15 and $10. His Aunty Anne who lives overseas has promised to send him $20. Once Argent receives the money from Aunty Anne, how much money will he have received altogether from his aunts and uncles for his eleventh birthday?***ead****R**Keywords / information: how much altogether, $5, $20, $15, $10, $20

Irrelevant information: birthday is on Friday, turning eleven, Aunty Anne lives overseas.

**peration****O**We have five different dollar amounts and need to know how much money there is altogether, so we need to add.

**alculate****C**Since we know we need to add, we can work out our algorithm and calculate the answer: 5 + 20 + 15 + 10 + 20 = 70

Our answer is $70 (don't forget the dollar sign).

**ense****S**We were asked to add five different dollar figures each of which was $20 or less. Our total figure needs to be:

1. more than each of the individual dollar amounts - which it is.

2. less than $100 (as each figure was $20 or less and 5 x $20 = $100) - which it is.

We can conclude that our answer makes sense.

If it didn't make sense we would work through the

**process again to find out where we made a mistake.****ROCS**

**Word Problem 2***If Tom's dad gave him $10 to go to the local store to buy an ice cream and the ice cream cost $3.20, how much change did he receive?***R**eadKeywords / information: how much change, $10, $3.20

Irrelevant information: the boy's name is Tom, his dad gave him the money

**peration****O**There is $10 and we need to know how much money is left after spending some, so we need to subtract.

**alculate****C**Since we know we need to subtract, we can work out our algorithm: $10 - $3.20 = $6.80

Our answer is $6.80 (don't forget the dollar sign).

**ense****S**We needed to subtract $3.20 from $10. If we round $3.20 to $3, we know our change will be close to $7 because 3 and 7 are

*best friends to 10*. Our answer makes sense.If it didn't make sense we would work through the

**process again to find out where we made a mistake.****ROCS**