Problem Solving 12
Our four step ROCS approach:
Read - the question carefully. Underline keywords / information and ignore any irrelevant (unimportant) information.
Operation - what operation do you need to solve the problem? Do you need to add, subtract, multiply or divide?
Calculate the answer.
Sense - does your answer make sense? If it does, you're probably correct. If not, work through the process again.
For multi-step problems you will need to work through this process more than once.
Word Problem 1
We have two apple trees in our backyard. There are five apples on one tree and eight apples on the other. How many apples do we have growing on our trees altogether?
Read
Keywords / information: how many altogether, five apples, eight apples
Information that is not important: trees are in our backyard
Operation
We have two different amounts and need to know how many altogether, so we need to add.
Calculate
Since we know we need to add, we can work out our algorithm and calculate the answer: 5 + 8 = 13
Our answer is 13 apples.
Sense
We added 5 and 8. Since we know 5 + 5 = 10 (the number of fingers we have) then our answer needs to be more than 10 since 8 is more than 5. Our answer makes sense.
Word Problem 2
My cousin, Tran and I love matchbox cars. If Tran has 18 matchbox cars and gives 6 to me, how many matchbox cars will he have left?
Read
Keywords / information: how many left, 18 cars, 6 cars
Information that is not important: cousin's name is Tran, we love matchbox cars
Operation
We have a total amount and an amount given away, so we need to subtract.
Calculate
Since we know we need to subtract, we can work out our algorithm and calculate the answer: 18 - 6 = 12
Our answer is 12 cars.
Sense
We subtracted 6 from 18. The number 18 has 1 lot of ten and 8 ones. Since 6 is less than 8 we know the answer will be more than 10. Our answer makes sense.
Read - the question carefully. Underline keywords / information and ignore any irrelevant (unimportant) information.
Operation - what operation do you need to solve the problem? Do you need to add, subtract, multiply or divide?
Calculate the answer.
Sense - does your answer make sense? If it does, you're probably correct. If not, work through the process again.
For multi-step problems you will need to work through this process more than once.
Word Problem 1
We have two apple trees in our backyard. There are five apples on one tree and eight apples on the other. How many apples do we have growing on our trees altogether?
Read
Keywords / information: how many altogether, five apples, eight apples
Information that is not important: trees are in our backyard
Operation
We have two different amounts and need to know how many altogether, so we need to add.
Calculate
Since we know we need to add, we can work out our algorithm and calculate the answer: 5 + 8 = 13
Our answer is 13 apples.
Sense
We added 5 and 8. Since we know 5 + 5 = 10 (the number of fingers we have) then our answer needs to be more than 10 since 8 is more than 5. Our answer makes sense.
Word Problem 2
My cousin, Tran and I love matchbox cars. If Tran has 18 matchbox cars and gives 6 to me, how many matchbox cars will he have left?
Read
Keywords / information: how many left, 18 cars, 6 cars
Information that is not important: cousin's name is Tran, we love matchbox cars
Operation
We have a total amount and an amount given away, so we need to subtract.
Calculate
Since we know we need to subtract, we can work out our algorithm and calculate the answer: 18 - 6 = 12
Our answer is 12 cars.
Sense
We subtracted 6 from 18. The number 18 has 1 lot of ten and 8 ones. Since 6 is less than 8 we know the answer will be more than 10. Our answer makes sense.