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# May Maths Challenge

Are you ready to take on the May Maths Challenge? Try and work out the answer for each day's question, then check back here the following day for the answer! Why don't you see if you can find the answer quicker than a grown up or sibling can?

Friday 22nd May

What is XXIII + DIV? Show your answer in words and Roman numerals.

This question has multiple parts. First, you must read what the Roman numerals say, then carry out the addition, then change the answer back into Roman numerals.

What time is 18:35 in words? In 12 hour time?

It would be 25 minutes to 7 in words.

In 12 hour time, you would have written 06:35 pm or 6:35 pm.

Thursday 21st May

What time is 18:35 in words? In 12 hour time?

What is 10,000 – 5,312?

You may have chosen to use column subtraction here, or may have tried to do it mentally via partitioning.

5,312 = 5,000 + 300 + 10 + 2

We could subtract each of these parts from 10,000.

10,000 - 5,000 = 5,000

5,000 - 300 = 4,700

4,700 - 10 = 4,690

4,690 - 2 = 4,688

So, 10,000 - 5,312 = 4,688

Wednesday 20th May

What is 10,000 – 5312?

Use place value carefully here!

What is the next number in this sequence: 1, 4, 9, 16, __? How do you know?

The next number would be 25!

This is because there is a pattern in what is being added each time.

1 (+3) 4 (+5) 9 (+7) 16

Following this rule: +3, +5, +7, we can say that the next step will be to +9.

16 + 9 = 25

Tuesday 19th May

What is the next number in this sequence: 1, 4, 9, 16, __? How do you know?

Think carefully about this one - when you think you've recognised the rule, check it to see if it works every time!

How many ml in 6.74l?

We know that               1l           =        1000ml

We want to know         6.74l      =          ?ml

Looking at it like this shows us that we need to multiply the litres by 1000. So, we need to use place value!

Th   H    T     U    .     t      h

6   .     7     4       (x1000) (So we move each digit     6     7     4     0   .     0     0        3 places to the left.)

This shows us that 6.74l  = 6740ml.

Monday 18th May

How many ml in 6.74l?

Think about the conversion that you know - how many ml in one litre? Then, use this to help you.

How many cm in 1.52m? How do you know?

If we know that 1m = 100cm, we can use this to convert 1.52m into cm.

1m           =     100cm

1.52m      =     152cm

We need to multiply 1.52 by 100! So, let's use our place value headings.

H   T   U   .   t    h

1   .   5   2    (x100 so we move each digit 2 places to the  1    5   2   .   0   0     left)

What is the biggest number you can make with 4 2 8 1 5?

Thinking about place value here will help. We have 5 digits to use, which means we will need the following place value headings:

Tth Th H T U

To make the biggest number possible, put the largest digit in the highest value column, then work your way down in size.

So:

Tth  Th  H  T  U

8     5   4   2   1

If y = 12, what is the value of x in ‘y + 52 = x’?

Here, if we add in the value we know to the calculation, it will read:

12 + 52 = x

Then, all we need to do is solve the addition!

12 + 52 = 64, so x = 64!

Friday 15th May

If y = 12, what is the value of x in ‘y + 52 = x’?

This one isn't as tricky as it seems at first - just replace the letters with the values that you know.

What do you call an 8-sided shape? What are the properties of that shape?

Of course, it's an octagon! Any 8 sided shape is an octagon, but they can be regular or irregular. A regular octagon will have 8 equal sides and 8 angles of the same size, but an irregular octagon can have different length sides and different size angles.

Thursday 14th May

What do you call an 8-sided shape? What are the properties of that shape?

You know your shapes very well!

Calculate 3 x 18 + 4

Using BODMAS/BIDMAS was really important here!

So we know that:

B = brackets ()

O/I = orders/indices (squaring or cubing numbers)

D = division

M = multiplication

S = subtraction

We must first then, calculate 3 x 18. We can do this using a mental partitioning strategy:

18 = 10 + 8

We can first work out 3 x 10 = 30

Then work out 3 x 8 =  24

Then add 30 + 24 = 54

When we've got this, we can add the 4.

54 + 4 = 58

This means that 3 x 18 + 4 = 58

Wednesday 13th May

Calculate 3 x 18 + 4

Remember to use the correct order of operations here!

Which number is bigger, 132331 or 132313? Describe how you know.

First, write each number under place value headings:

HTh   TTh   Th   H   T    U

1      3       2    3    3    1

1      3       2    3    1    3

When we do this, we can see that each number has the same value in each column apart from the tens and units. Which number has the most tens? 132,331. Therefore, this is the bigger number, as it has 3 tens, whereas 132,313 only has 1 ten.

Tuesday 12th May

Which number is bigger, 132331 or 132313? Describe how you know.

For this question, use place value!

Half of a number is 117, what was the number?

If we wrote this down it would look like this:

? divided by 2  = 117

So, how do we find the missing number here? By using the inverse!

117 x 2 (which is the same as 117 + 117)

We can use our partitioning method of doubling!

117 = 100 + 10 + 7

100 x 2 = 200

10 x 2 = 20

7 x 2 = 14

200 + 20 + 14 = 234

Monday 11th May

Half of a number is 117, what was the number?

Think about what the calculation would look like written down, this might help you visualise what you need to do.

What is double 167? Can you work it out 2 ways?

Okay, doubling is simply multiplying by 2. There are a few ways you may have chosen to do this. You could have done:

167 x 2 =

167 + 167 =

Both would give you the same answer. However, you could also have partitioned the number, like we did in school, then added the values at the end. Let's look at it that way!

So:

167 = 100 + 60 + 7

Double 100 = 100 x 2 = 100 + 100 = 200

Double 60 = 60 x 2 = 60 + 60 = 120

Double 7 = 7 x 2 = 7 +7 = 14

Now, we must add each of those values:

200 + 120 + 14 = 334

What is 4.2 – 1.9? How did you work it out?

Here, you could have done column subtraction. However, you may have chosen to use rounding and adjusting.

For example, you could have rounded 1.9 up to the nearest whole number, 2.

Then, you could have subtracted this from 4.2:

4.2 - 2(.0) = 2.2

Is this the correct answer? Not yet! We must now adjust the answer. We subtracted 2.0, when we only needed to subtract 1.9. This means we have subtracted 0.1 too much - so we just add it back on!

2.2 + 0.1 = 2.3

There we have it!

4.2 - 1.9 = 2.3

How many degrees in a right angle?

90 degrees... You are all angle superstars!

Friday 8th May

How many degrees in a right angle?

This one needs no explanation... I know you all know this!

What is 15, 356 rounded to the nearest 100?

You should have underlined the hundreds digit and circled the tens digit. There are 5 tens in the circle, which means we round up.

Thursday 7th May

What is 15, 356 rounded to the nearest 100?

Another rounding question - you're all fab at these!

(4 x 3) – 4 = 9. Is this right? Why?

For this question, using the correct order of operation was really important. We should always complete the calculation inside the brackets first.

So, 4 x 3 = 12.

Next, we can carry out the subtraction.

We know that:

4 x 3 = 12

12 - 4 = 8

Wednesday 6th May

(4 x 3) – 4 = 9. Is this right? Why?

For this question, remember the order of operations:

BODMAS (or BIDMAS)

Thomas says, “If y-12=6, then y must be 6” Is he right? How do you know?

For this question, a number line would come in handy. Thomas believes that 'y' is being used to represent the number 6. So, he

says that 6-12=6. We can use a number line to check this.

Start on 6, and subtract 12.

6, 5, 4, 3, 2, 1, 0, -1,-2, -3, -4, -5, -6

Hmm... we've ended up in negative numbers. By using a number line, we can see that 6-12= -6. So Thomas is incorrect and we can use the number line to show this.

To work out what 'y' is, we can do the inverse. So, 6 + 12 = 18.

Let's check if it's correct:

18-12=6

So - the 'y' represents 18!

Tuesday 5th May

Thomas says, “If y-12=6, then y must be 6” Is he right? How do you know?

For this question, you might want use a number line...

What number is represented here: MMCCDXI?

Did anyone spot the problem here?

This is because:

M = 1000 (MM = 2000)

C = 100 (CC = 200)

D = 500

XI = 11

So does it work?

Monday 4th May

What number is represented here: MMCCDXI?

Remember the rules for Roman numerals! If you are struggling, check the Roman Numerals 2Do which has been set on Purple Mash!

Sunday 3rd May

What is 142, 533 rounded to the nearest 1000?

You're all fantastic at rounding! Remember to underline the digit you are being asked to round to and then circle the digit to the right of this - this is the important one!

Is 1.5 x 100 the same as 15 x 100?

Place value was needed here! When you multiply by 100, each digit moves two places to the left - but the decimal point never moves!

So, 1.5 x 100 would give you 150, as the 1 would move 2 places to the left from the units to the hundreds column, the 5 would move from the tenths to the tens and then you would need to pop a placeholder in the units column.

15 x 100 = 1500, as the 1 would move from the units to the hundreds column, the 5 from the units to the hundreds column and then you would need to pop placeholders in both the tens and the units column.

Saturday 2nd May

Is 1.5 x 100 the same as 15 x 100?

Remember the rule for multiplying by 100 - place value is super important here! If x + 4 = 13 + 37, what is the value of x?

To solve this calculation, first you needed to get the answer to one

side of the balanced equation. So, what is 13 + 37?

When you have this answer, you can use the inverse, as x + 4 should equal the same as 13 + 37.

So, 13 + 37 = 50

50 - 4 = 46

x = 46

Friday 1st May

If x + 4 = 13 + 37, what is the value of x?

Oooh...algebra! This is just a missing number problem - the x could be a question mark, a star, a goldfish, an alien...its job is  simply to represent a missing value.

It's also a balanced equation - think about what the = sign means!

Give it a go, then check back here tomorrow for the answer! If you want to send your answer to me on Purple Mash 2Email, please do! Top