**Bob is trying his hardest to solve the problems below but he keeps getting them wrong.**

**Please IDENTIFY whether the calculations below are correct or incorrect? If they are incorrect please EXPLAIN where he has made a mistake and correct the calculations.**

**Firstly, complete the calculation.**

**Secondly, identify where the error has been made?**

**Thirdly, explain what the error was (place value, incorrect column, exchanging, multiplying incorrect digits etc)**

**Fourthly, carry out the calculation and write the correct answer.**

**Key vocabulary:**

**Multiply, lots of, place value, digit, column, subtraction, exchange, larger, smaller, value.
First step….
When multiplying…
After subtracting…**

The third question is wrong because on step B Bob wrote that 4-6=0 but your suppose to exchange it so that’s the error.

1.This is wrong because 6 x 0 = 0.

1 bob needed to times 7×6 firstly which equally 42. Then times 0 by 6 which should have been 0. An then 1 times 6. Which is 6. The answer should have been 642.

Then you add 600 to 642 which is 1242. Then u subtract 115 from 1242 and the final answer is 1127.

Bobs answer was incorrect because he made a mistake at the beginning his answer to 6 x 0 was 6 but it should have been 0.

3. The mistake that Bob made is that he put his answer to 4 plus 4 as 4 but it should have been 8 an the answer should have been 1589 and not 1549.

1 bob needed to times 7×6 firstly which equally 42. Then times 0 by 6 which should have been 0. An then 1 times 6. Which is 6. The answer should have been 642.

Then you add 600 to 642 which is 1242. Then u subtract 115 from 1242 and the final answer is 1127.

Bobs answer was incorrect because he made a mistake at the beginning his answer to 6 x 0 was 6 but it should have been 0.

3. The mistake that Bob made is that he put his answer to 4 plus 4 as 4 but it should have been 8 an the answer should have been 1589 and not 1549.

1 bob needed to times 7×6 firstly which equally 42. Then times 0 by 6 which should have been 0. An then 1 times 6. Which is 6. The answer should have been 642.

Then you add 600 to 642 which is 1242. Then u subtract 115 from 1242 and the final answer is 1127.

Bobs answer was incorrect because he made a mistake at the beginning his answer to 6 x 0 was 6 but it should have been 0.

3. The mistake that Bob made is that he put his answer to 4 plus 4 as 4 but it should have been 8 an the answer should have been 1589 and not 1549.

Then you add 600 to 642 which is 1242. Then u subtract 115 from 1242 and the final answer is 1127.

Then you add 600 to 642 which is 1242. Then u subtract 115 from 1242 and the final answer is 1127.

Then you add 600 to 642 which is 1242. Then u subtract 115 from 1242 and the final answer is 1127.

Then you add 600 to 642 which is 1242. Then u subtract 115 from 1242 and the final answer is 1127.

Then you add 600 to 642 which is 1242. Then u subtract 115 from 1242 and the final answer is 1127.

Then you add 600 to 642 which is 1242. Then u subtract 115 from 1242 and the final answer is 1127.

Then you add 600 to 642 which is 1242. Then u subtract 115 from 1242 and the final answer is 1127.

Then you add 600 to 642 which is 1242. Then u subtract 115 from 1242 and the final answer is 1127.

Then you add 600 to 642 which is 1242. Then u subtract 115 from 1242 and the final answer is 1127.

You first look at your ones column and do 7 times 6 which egauls

42

2.after you complete it which makes 6 then you 6 times 100 600 add your total together to find the answer 648 but now you now you go on the second step you have to 648 that’s how you do it

Homework

1.first you multiply the ones (7times 6) which equals 42

2. multiply the tens (0 times 6) which is 0 and

3.6 times 100 is 600 but where Bob wrote 6 times 0 is 6 so you have multiplyed the tens wrong so therefor the answer is wrong.

1.firstly 6×7=42

then 6×0=0 not 6 this is error

then 6×100=600

adding together get 642

642-115=527

2.firstly 9×3=27

then 9×20=180

next 9×100=900 this is where error is

to complete calculation add these together gives

1107-105=1002

3.firstly 7×7=49

then 7×20=140

then 7×200=1400

adding gives 1589 this is where error is in adding 10’s column gives you 8 not 4

1589-669=920

1.The first calculation is incorrect because 0 times 6 is not 6 because 1 times 6 is 6 so the correct answer is 642.The answer of 642 takeaway 115 is 527.

2.In this question the error is that a hundred times nine is not 9000 and it is suppose to be 900.In step B the answer is supposed to be 1107.Now you calculate 1107 takeaway 105 which is 1002.

3.In step A the answer to 49 add 140 and 1400 is not 1549 because Bob might have put the numbers in the wrong column. In step B you need to calculate 1589 takeaway 669 which is 920.

1) First of all you added the total wrong it should be 642. Because of that mistake the whole sum is wrong. The real answer should be 527.

2) Bob is correct but he forgot his ➖.

3) The firs bit is wrong it should be 1589 it is all wrong it should be 1130

I mean incorrect!🙊🙊

The error is that bob did 6x1it is 0x6.

1.First, you look at the ones column and calculate 7×6, which is 42.

Next, you look at the tens column, but just put 0 because you can’t times 0.

Then you look at the hundreds column and calculate 100×6, which is 600.

After that, add them together.42+0+600=642.

Finally, take away 115, you will have exchange, carry over.The whole answer is 527.

Ok Nithuisha

First you need 6 times 7 which equals 42 and then you will calculate 6 times 0 that equals 0 not 6 .

Then you multiply 6 times 100 that equals 600 .

Now you add your total together and you will get the answer 648.

Finally you take away 155 from 648 and then you will find your answer

1.first you look at the ones column and do (7times 6)which equals 42.

2.After that you have to complete it which makes 6.

3.then you times 6 times 100=600.

4.Add your total together to find the answer 648 but now you go on to the second step.

5.You have to do 648-115=533

But first you to see if you have done some carrying over{EXCHANGE}your answer is 533

1.You first at your ones colum and do (7 times 6) which

equals 42.

2.After that you have to complete it which makes 6.

3.Then you do 6 time 100=600.

4.Add your total together to find the answe 642 but now you

go on the second step.

5.You have to do 642-115=527

But first you have to see if you have to do some caring

over {Exghange}

You answer is 527

1.You first at your ones colum and do (7 times 6) which

equals 42.

2.After that you have to complete it which makes 6.

3.Then you do 6 time 100=600.

4.Add your total together to find the answe 648 but now you

go on the second step.

5.You have to do 648-115=533

But first you have to see if you have to do some caring

over {Exghange}

You answer is 533.

1)Firstly you look at the ones column (6 x 7) which equals 42.

2)Secondly you need to multiply (0 and 6)which equals 0.

3)Next you do (100 x 6) which equals 600.

the error was that it was supposed to be 0x6 but it was only a 6. the error was in the tens column but after subtracting it would be 527.

1.This is false because it is asking 6×0 and that is 0 therefore the answer is wrong .

2.This is also false because it is asking you to do 9×100 which is 900 not 9000 so this is wrong.

3.You cannot do 5-6 so you are meant to exchange so this is wrong

1) The error that Bob has made is that 0✖️6 is not 6 it is 0 and the adding is wrong it is not 2 it is 8. Also for the subtraction it is not 648 -115 it is 642-115. Now you have changed the calculation the answer should be 527 it should not be 533.

2) The error that Bob has made is that the multiplication answer is not 9207 it is supposed to be 1107. Also the subtraction is not 9207-105 it is supposed to be 1107-105. Now when Bob changes the calculation the answer should be 1002 it is not supposed to be 9102.

3)The error that Bob has made is that 4+4 is not 4 it is supposed to be 8. Also the subtraction calculation is not 1549-699 it is supposed to be 1589-669. When you subtract 1589-669 the answer will change and the answer should then be 920 not 2200.

1) 107×6 115= 648 false answer 527

Firs you look at the ones column which is 7×6=4) then you do 0x6=0 next we do 100×6 =600.

The mistake bob has made is that he wrote 6 for 0x6 but it was incorrect the answer should be 0.

The answer to 107×6-115=527

2) 123×9-105=9102 False answer 1002

Firstly we have to do 3×9=27 then 9×20=180 after you have to do 9×100=900.

The error he has made is that he wrote 9×100=900 but he wrote 9000. the answer to 123×9 -105=1002.

3)227×7-669=2200 False answer 920

first you have to do 7×7=49 then 7×20=140 next you have to do 7×200=1400.

The error bob has made is when he was adding the tens column he didn’t write 8 he wrote 4 .

The answer to 227×7-669 =920

I did mine on paper mrs street

(107 x6 )-115=

1.Calculate (7×6) the answer would be 42 then this is when Bob got it wrong he did 0x6 the answer wouldn’t be 6 it was 0 then u have to do 6x 100 not (6×1) the answer would be 600. Then you have to take away 642 from 115 then take away 5-2 it can happen so take away 5 from to it would be 3 then take away 4 from 1 the answer would be 3 then 600 take away 100 the answer would be 500 . Then the total would be 533

Homework

Firstly, you multiply 7and 6(which is 42),then you multiply 0 and 60(which is not 6!),after that you x 6 by 100 which is 600,add them all together which makes 642 but that isn’t the answer. You then takeaway 115 from 642 which is 533.

Secondly,Bob make an error because he did 0x6 but you can’t multiply but bob put 6 and he forgot that 0 can’t be multiplied. And because he made a silly mistake it affected the whole calculation which caused him to get the wrong answer.(this was all I had time for)

Maths homework:on paper

1)❌ first you multiply 6×7 which is 42 then you multiply 6×0 which is 0 not 6 this is the mistake Bob had made which affected the whole sum now you move onto the hundreds where you multiply 100 times larger the answer is 600.This calculation is false because the real answer is 642 now you take it away from 115.

2) ❌This whole calculation is false because he went smoothly until he came onto the hundreds when he multiplied 9 by 100 which is 900 not 9000 which caused the whole calculation wrong therefore the answer for step A is 1027 not 9027. Once you have taken it away from 105 now you get the answer.

3) This sum was right when he added them altogether than struggled with adding them up which is wrong because 4+4 equals 8 not 4 anyway the real answer is 1,589 not 1549. This is the final answer of the day.

1.Firstly look at the ones colum and multiply 6×7 which is 42 second step multiply 6×0 which is 0 not 6,finally Bob needs to multiply 6×100 which is 600,the answer for this question is 648, then you need to solve step B which is 648 – 115 which is 533 this is the final answer to this question. The mistake that Bob has made is the 6×0=0 but Bob wrote 6×0=6.

The first step is to start by multiplying 6×7 on the first column. This equals to 42.secondly you multiply 6×0 which is 0 not 6.after this you multiply 6×100 which equals to 600.next you have to add all of your answers and this should equal to 648. Then you need to take away 115 from 648 which should equal 533 and this is your final answer.the mistake that Bob has made is that he thought 6×0 is 6 however it is not 6×0 equals to 0 so this has made all of his calculation wrong.

Maths Homework

1.True

2.The second calculation is incorrect because Bob did 9✖️1000 that is why the answer is incorrect.

Remember Eesa you need to explain why it is incorret

1. You first look at your ones column and do\7 times 6 which equal 42.

2. After that you have to complete it which makes 6.

3. Then you 6 times 100=600

4. Add the total together to find the answer 648 but now you go on the second step.

5. You have to do 648 – 115=533.

But first you have to see if you have to do some carrying over exchange.

Your answer is 533.

You mean times Hanna

Yes Nithusha

1. False because he times it wrong

2. This is wrong because it’s not 9000 that’s why it’s wrong

3.Wrong because he added his numbers incorrect

Remember Abir to explain in detail

1 Bob has multiplied 6×0 and his answer was 6 when it was zero

it was supposed to be 42+0+600=642 and not 648

2 It is wrong because instead of multipling 9 by 100 he multiplied it by 1000

3 Is wrong because he never added the other 4

First you need to multiply 6 × 7 which equals 42 and then you will calculate 6× 0 that equals 0 not 6. Then you multiply 6× 100 that equals 600. Now add your total together and you will get the answer 648. Finally you take away 115 from 648 and then you will find your answer.

Maths Homework

False

1.Firstly, you look at the ones column and multiply 6×7 which equals 42,secondly you need to multiply 6×0 which is 0(not 6).Then the final step to complete step (A) is to multiply 6×100 which is 600.So the answer for step (A) should be 642.Just because Bob made a silly mistake the whole sum was affected.

False

2.Bob has started really good but ended badly

The mistake that Bob has made that 9×100 is 9000.Well 9×100 isn’t 9000 because you need to 100 times 9.To explain in detail the 9 won’t become 9000 because you are making the 9 1000 times bigger ,so the answer the step (A)is 1107 not 9207.

False

3. Bob has multiplied all the numbers correctly but when he was adding all of his multiples together he messed up. When

Bob was adding his tens column, the sum was 40+40 (which is 80)he wrote that the answer was 40.

maths homework

equals 42, step two you have to do 6 times 0 wich equals 0 then the last step is too to do letter (a) 6times 100 wich is 600 then the answer dhould be 642.

false

2.he di good but 9times100 isnt 9000 its 900 because 100times not 1000 so thts

What equals 42?

1.False because when he multiplied 0 x 6 they multiplied 1×6 instead and the correct answer is 642.

In the second step the correct and final answer is

2.False because he multiplied 100 with 9 he wrote the 9000 instead of writing 900 and the correct answer is 1002.

3.false because he didn’t add the numbers correctly and in the second step he add the thousand, hundred, and tens Column .He was supposed to exchange because when subtracting the hundreds column the five hundred is at the top of the six hundred so he had to take a thousand away from the thousand column then add the one thousand to the 500 and the correct answer is 920.

Maths homework

(107×6)-115=648

Firstly you look at the ones column (6×7=42) then (0x6=0) after (100×6= 600).

The error that has made is that instead of writing 0 for 0x6 he wrote 6 which is incorrect.

The error was in the tens column.

After subtracting, the answer will be 527.

(123×9)-105=9102

Firstly we do (3×9=27), (20×9=180) and (100×9=900).

I think the error that Bob is made is that, when he was trying to do 1×9 because he was unsure what 100×9 was that he accidently made it oneasy thousand times bigger.

The error was made in the hundered column.

The correct answer is 1002.

(227×7)-669=2200

First do (7×7=49), (20×7=140) and (200×7=1400).

The error that Bob has made is that in the addition bit 4+4 is 8 instead he wrote 4.

The error was made in the tens column.

The correct answer is 0908.

Alish you don’t say do you say multiply

I mean Alisha

1. First you need to canculate 7×6 it equals 42.

2. Next Bob needed to canculate 0x6 which equals 0 and bob has gone wrong there because he had multiplyed it incrorrectly.

3. Then you have to multiply 6×100 and it equals 600 then add up all the numbers then it equals 642.

Well identified Abdas :) Please identify the errors made in the other two calculations also.

Spellings: ‘calculate”multiplied’

I did it on paper

Good work Arshdeep, but you must complete the calculation on paper but write an EXPLANATION on the blog sharing where Bob made the mistake and what the correct answer is.

Miss I am sick and don’t know what happend

Hello Abir,

I hope you are feeling better.

Use your multiplication and subtraction skills to check whether the calculations above are correct or incorrect.

If the calculation is incorrect, use the correct vocabulary to write an explanation sharing where Bob made the error.

1)The first calculation is false because you have to do (107×6)-115 so you do 6×7 which is 42 and then you do 6×0 now this is where Bob went wrong he wrote down 6 instead of 0 after that you calculate 100×6 which equals 600.The answer is 642.Now we move on to the subtraction part.The calculation for this part is 642-115.And when you finish that you get your answer which is 527.

Well done Hamda, remember all three calculations must be checked, errors must be explained and the correct answer must be shared.

Ok Miss Ahmed

1)The first one is false because if we do 6×7=42,0×6=0,100×6=600 and he we add all to these numbers the will become 642 but Bob says it is 648 so he is wrong but this is a 2 step problem so he has to take away 642 and 115=527 but Bob says it is 533 because he done 648-115=533 and he is wrong he’s mistake was he done 6×1=6 but he suppose to do 6×0=0

2)the second one is false bescause if we do 9×3=27,9×20=180,9×100=900 but the mistake that Bob did 1000×9=9000 but he should have done 100×9=900 and if we add all these numbers the answer we will get is 1107 but he got it wrong because he wrote 9207 after multiplying we do 105-1107=1002 but what he done is 9207-105=9102 but he got it wrong the mistake he done is 1000×9=9000 but he suppose to do 100×9=900

3)this is false because adding he got it wrong it suppose to be 1589 but he done 1549.In take away it is wrong Bob add the 4+6 instead take away correct answer is 880.

1)(107×6)-115=553

The first mistake Bob made is that 6 x 0 doesn’t equal 6 it equals 0.

When mulyiplying 6 x 100 you had to make it 100 times bigger.Once you made it 10 times bigger add it all together and the answer will leave you with 642.

After you takeaway 115 from 642 you will get your final answer.

2)(1 2 3 x 9)- 1 0 5

The first step you need to do is times 9 by 3 which is 27 the the second step you need to do is multiply 9 by 20 which is 180.Now this is the part that bob doesn’t understand you multiplyed 1000 times bigger instead of 100 times bigger if you do it 100 times bigger your correct answer is 900.Now that you have your correct answer add it all together your answer is 1007.now you do 1007 – 105 and you will get your final answer for the calculation.

3) (227 x 7)-669

The first step you need to do for this calculation is 7 x 7 which is 49 then you do 7 x 20 which is 140 because you know that 7 x 2 = 14 you just add a place holder and you get 140. The second step you need to do is 7 x 200 which is 1400. Now once you done that you add it all together 9+0+0=9 bob thinks 4+4 =4 but actually it is 8 because if you add another 4 onto 4 you get 8.Now you add 1+4 which equals 5 next you do 1+ nothing which equals one.you answer is 1589.

Now you do 1589 – 669 and you will get your total.

1)First you look at your ones column and multiply 7 by 6 which equals 42,then you have to complete the tens column by multiplying 6 and 0 which equals 6,Once you have done that,you need to multiply 6 and 100 which equals 600.After that you need to add the answers that you got and it all should add up to 648.But now we need to move on to the second step which is taking away 115 from your answer that you just got(648).Once that is done,you have found your answer which is 533.

So this Correct.

1.You first look at your ones column and do(7 times 6)which equals

42.

2.After that you have to complete it which makes 6.

3.Then you 6 times 100=600

4.Add your total together to find the answer 648 but now you go on the second step.

5.You have to do 648 – 115=533

But first you have to see if you have to do some carrying over[exchange].

Your answer is 533.