Tag: mental arithmetic

As we approach the end of the Spring Term it’s time for another set of mental arithmetic questions. This week it is a mixed bag of calculating, including money.

The first two questions in each set look at adding 4 small numbers. The difficulty in doing this should not be underestimated as it is as much to do with memory as addition skills. This is a much easier question if children can see the numbers, either on the printed page or on a whiteboard.

The next two questions look at addition and subtraction of money. In both cases the pounds stay the same and the pence have to be added or subtracted.

Question 6 can cause difficulties. It asks, ’10 taken from a number is 17. What is the the number?’

Watch out for the child who hears the numbers and just subtracts 10 from 17!

Finally we have some doubling questions. By now children in Year 3 should know the double of small numbers up to ten and be able to work out the double of numbers in the teens. Eventually it is hoped they will know these off by heart.

Year 3 Mental arithmetic (sets 45 and 46)

 

This week’s mental arithmetic questions for Year 3 are all about fractions. The first couple of questions are simple, finding halves of multiples of 10. Most children learn the halves of even numbers up to 10 but find it harder to work out half of numbers such as 30 or 50, where this knowledge is not so useful.

The next two questions look at a different aspect of fractions; sharing one whole one into equal parts and naming the parts. Questions 5 and 6 look at finding a quarter of numbers.

Probably the hardest two questions involve counting up in quarters and finding a number half way between two others. Finding the number half way between three and a half and four is quite tricky and children need to have spent some time using number lines and counting in quarters to be successful with this.

Finally a couple of questions which test knowledge of the meaning of a fraction and that the larger the bottom number (denominator) the smaller the fraction will be (if the top number (numerator) is the same).

Year 3 mental arithmetic (sets 43 and 44)

This week’s mental arithmetic questions for year 3 cover just multiplication and division. Year 3 is the start of the learning ‘times tables’, and by the end of the year children should be confident with at least the 2, 5 and 10 times tables as well as developing 3x and 4x.

Some teachers argue that children should also learn the ‘division tables’. These are the equivalent facts for division. For example, the dividing by 5 table would go like this:

5 divided by 5 is 1

10 divided by 5 is 2

15 divided by 5 is 3

20 divided by 5 is 4

25 divided by 5 is 5

30 divided by 5 is 6

35 divided by 5 is 7

40 divided by 5 is 8

45 divided by 5 is 9

50 divided by 5 is 10

Although it must be said that children who really know the ‘times tables’ off by heart can very rapidly work out these facts. Whichever way they do it children should be able to answer a question such as; ’16 divided by 2′ in a second or less.

Year 3 mental arithmetic_(sets 41 and 42)

An ability to calculate mentally lies at the heart of being successful with number work. Mental methods need to be emphasised and practised on a regular basis and these year 3 mental arithmetic pages can certainly help towards this.

These two sets of ten questions concentrate on counting on and back in single figures or whole tens. Children will often use their fingers to count on or back but it does help if they can begin to know these facts off by heart. For example counting back 7 from a number with a 2 in the units will result in an answer with 5 in the units. By the end of year 3 children should also be confident with counting on and back in whole tens from any 2-digit number.

Year 3 Mental arithmetic (Sets 37 and 38)

Exactly half way through the school year with the publication of sets 35 and 36 mental arithmetic for Year 3. This is quite a mixed bag of questions covering number and measurement.

Two of the questions in each set look at time, which is often a problem for children. These two questions look at time intervals between two events. For example:

‘A TV programme starts at 4.50 and ends at 5.20. How long does it last?’

This presumes that knowledge of 60 minutes in an hour is known and the best way to proceed is to add on to the next whole hour (10 minutes) and then add on the extra minutes (20 minutes) to get 30 minutes.

These questions can be read out loud and children answer on paper, or they can just call out the answers, or show them on digit cards etc. Alternatively they can be given the question sheet to look at and record answers.

Year 3 Mental Arithmetic (sets 35 and 36)

This week’s mental arithmetic for year 3 looks at place value, number sequences and patterns as well as some quick addition.

One of the early questions asks what’s the largest number that can be made from the digits 2, 5 and 4. This is partly an ordering skill, making sure the largest digit is in the hundreds, second largest in the tens and smallest in the units. Some children find it quite difficult to retain three digits in their head and then manipulate them.

To find the next number in a sequence requires several skills. Firstly to listen carefully to the numbers, then to work out the pattern or rule and as to what is happening from one number to the next and thirdly to work out what the next number will be. These questions are kept at a fairly simple level and are all addition patterns.

There are also a couple of ‘odd number’ questions to check that children know about odd numbers.

Year 3 mental arithmetic: (sets 33 and 34)

This week the questions are all in the form of word problems. Generally children find these harder than just ‘sums’ because they are not told what operation needs to be carried out to reach the correct answer. Indeed, sometimes it can be tricky. Looking at the question,

‘I think of a number and subtract 10. The answer is 27. What is my number?’

Immediately the word subtraction will come to mind as it is used in the question. But, in fact, an addition has to be done to find the correct answer.

Several questions also require a good knowledge of the 2x, 5x and 10x tables.

If you are reading these out for children to answer be sure to read each question slowly and at least twice. The first time the question is heard the child will probably be thinking about what needs to be done. The second time reinforces the numbers involved.

Year 3 mental arithmetic (sets 29 and 30)

This week’s sets of mental arithmetic questions concentrate solely on addition and subtraction. There are many different strategies that can be used, depending very much on the numbers involved.

For example:

7 plus 147 can be done quickly by counting on 7, or by  knowing off by heart that 7 and 7 is 14

9 plus 129 can be done by adding 10 and subtracting 1

44 plus 16 can be done by adding the tens first and then the units, or vice versa.

It is important that children have all these techniques at their fingertips, and one way to make sure they have is to point out the many possible ways and which are the most efficient.

Year 3 mental arithmetic (sets 27 and 28)