help solve question 50,nfer maths test 11a in ONE MINUTE

[kenta]

A milkman and a baker deliver to the same house.In a period of 28days,the milkman calls every second day and the baker every third day.
They meet at the house twice in the first 7 days.
How many more times do they meet during the 4 week period?

Answer is 3.
How can a child work this out in one minute?please help.

[patricia]

A milkman and a baker deliver to the same house.In a period of 28days,the milkman calls every second day and the baker every third day.
They meet at the house twice in the first 7 days.
How many more times do they meet during the 4 week period?

Answer is 3.
How can a child work this out in one minute?please help.

Quickly write out the 2 and 3 times table....

2 4 6 8 10 12 14 16 18 20 22 24 26 28

3 6 9 12 15 18 21 24 27

They both meet on day 1 then day 6 of the first week.

Extra days that come from the same times table are 12 18 24

Thats about 15/20 seconds to write out the numbers and a few more seconds to find the duplicate numbers.

The art with these questions is to write out very quick notes, too many children want to do it in their heads, they do not understand that it its actually quicker to write it out! I would have encouraged the child to ring the duplicate numbers.

Patricia

[yoyo123]

Just as Patricia says ..I am great believer in diagrams.

[patricia]

Dear Yoyo123

I am such a 'meanie' tutor, if a child gets a question wrong and has NOT made notes, I take an extra mark off!

My standard quote... 'Well, where are your notes?'

If you look at my rules for the test No 5 it says make notes where appropriate, then in brackets, you know when to make them!

Patricia

[kenta]

Thank you Patricia.

[Anne42]

Thanks , i was wondering how to do that . Daughter hasn't done that test yet , so she might know anyway , but at least i'm prepared now .

[SM]

They both meet on day 1 then day 6 of the first week

I'm being a pedant here probably........

If the milkman calls every second day, he wouldn't be there on day 1 and day 6.

Also, if he was there on day 1, how can you then use the two times table beginning from zero to calculate the rest of the meetings?

It's got to be:

They both meet on day 1 and day 7 of the first week.

Then you count in 2s and 3s from there:

1 3 5 7 9 11 13 15 17 19 21 23 25 27
1 4 7 10 13 16 19 22 25 28

So the three other meetings are on the 13th, 19th and 25th days.

[patricia]

Dear SM

Agree.

Luckily they only have to provide the number of days, not the actual dates. Same principle applies for the working out, adding on in 2s and 3s and most importantly, MAKING NOTES...

Patricia

[fm]

They wouldn't have to do this in one minute. They would have spare time over from all the simpler questions earlier. Some children have the first 25 in NFER practice test finished in 10 minutes, leaving 40 minutes for next 25.

[kenta]

Yes,both Patricia and SM are right.My daughter actually used SM's method when I showed her Patricia's method.
Both are right.Thanks once again.