# Year 4 Maths Challenge

Identify the mistakes made in this calculation and explain the errors made.

Write a detailed step by step instruction guide for how to solve the calculation correctly.

## 13 thoughts on “Year 4 Maths Challenge”

1. Ali Samira

You have done the sum and answer wrong.
1.first,you have to write the sum.
2.Secondly,you have to write 300+40+1 then you write 100+50+2
3.Then,subtract 100 from 300,40 subtract 50,1 subtract 2.
4.Finally,the total is 200.

2. Daud Leena

I think you got the answer wright but the symbols were in the wrong places.
Don’t put addition symbole put nothing just leave a gap between. The problem is soved.

• Daud Leena

oops I made a mistake I needed to write in the step by step instrouctions

3. Hussain Alina

You have done this wrong because in subtraction you don’t put add signs in between your number.Also you can’t do 40 – 50 you have to borrow a 100.Like this.

1.Partition both of the number into hundreds ,tens and units.
2.underneath it draw a line and subtract the numbers that are underneath one another.
3.If you have a bigger number underneath the smaller one
then borrow from the next column and write the added number small on top of the column.

4. Mohammed Nidal

Step 1
You need to partion the numbers so that you get this
300 40 1
200 50 2
Step 2
You can’t do 1-2 so you borrow from the 40.The 40 will become 30 and the 1 will become 11.Now you do 11-2 which is 9.
Step 3
You can’t do 40-50 so you should borrow from the 300.The 300 will become 200 and the and the 40 will become140.Now you do 140 – 50 which is 90
Step 4

5. Shamba Fardosa

the mistakes are you have done 40 add 50 which you can not do you have to cross a boundtrie so the 40 will turn to a 30 because you took away a 10 40-10=30 now go to the 50 and take away 10 so it will be 40 so 40-30 is possible so it will become 10 then you go on to the unit collum you steal a ten from the 40 and add it to 1 so 1 add 10=11 so the answer will be 219

6. Samira Fareedah

Mistakes
[1]Your first mistake is subtracting the units.You can’t subtract 2 from 1.So you have to borrow from the tens.You take away ten from 40.So it becomes 30.Then add the ten to the units.So the 1 becomes 11.Then take away 2 from 11.So the answer is 9.

Then go on to the tens.30 take away 50.You can’t do that.So You need to borrow again.Now you borrow from the hundreds.So take away 100 from 300.So it becomes 200.Then 30 becomes 130.Then take away 50 from 130.So the answer is 80.

Then go on to the hundreds.Remember 300 became 200.So it is 200 take away 100.That is 100.

There you go,you have your answer.189 and remember if you can’t take a number away from another number,you will need to borrow.

7. Phillips Sophie

step 1
you need to partition the numbers

step 2
after you have done that write the subtract or adittion sighn and draw a straight line under the numbers that you have partitioned.

step 3
then subtract or add the numbers that you have partitioned altogether.if the number is smaller than the bottom colum than cross out and borrow from the hundreds tens and units colum.

step 4
finally total the amount that you addied or subtracted

• Laura Tarn

Well done!
Work out the correct answer on a piece of paper please Sophie and show me at school.

8. Abbas Amina

Mistakes

1)The first mistake is the subtracting of the units.You can’t do 1-2 because the biggest number always goes first but another thing you can’t do is switch the numbers around because that will make your answer wrong.To work out the answer to 1-2 which you can’t do you need to borrow from the next column by subtracting ten from the next column and adding ten to the column that does not work,but don’t add it to the number below because that is the big number and you add it to the small number because that is the number you can’t take away from.
2)Then again you can’t do 40-50 because 40 is smaller than 50 so this time you take away from the hundreds and you take away 100 and add 100 to the tens.
3)This is the last mistake.300-100 is 200 but in this sum it is not because you have already carried 100 over to the tens column which makes the 300 100 less which is 200.So the sum is actually 200-100 which is not 200 it is 100.

Because the steps were done wrong the answer is wrong the answer is actually 189.

Really hope I win can’t wait to know what the prize is.

• Laura Tarn

Brilliant detail Amina.

Can you use the same method to solve 234 -147? Write down your answer and show me at school!

9. Naseer Omayah

The erros you made was the bit when you were totaling you answers you cant do 40 subtract 50.

Step1:first write down the sum and partition the numbers into hundreds tens and units.

Step2:After you have done that write the subtract or addition sighn and draw a straight line under the numbers that you have partitioned.

Step3:Then subtract/add the numbers that you have partitioned altogether but, if you have a number that is smaller number than the bottom colum than cross the smaller number out and borrow from the hundred/ten/unit colum.