I am so impressed with your thinking! I have to admit I had a bit of a problem with last weeks...my first answer was 25 days then I worked it out again and got 20.
Last weeks answer: 5 totally clear days and 15 half and half.
In the 15 half and half days:
7 of the clear mornings were followed by rain, 8 of the clear afternoons were preceeded by rain. 20 days of the vacation.
Last weeks answer: 5 totally clear days and 15 half and half.
In the 15 half and half days:
7 of the clear mornings were followed by rain, 8 of the clear afternoons were preceeded by rain. 20 days of the vacation.
This weeks problem
This stairway is made of cubes. How many cubes would be needed to make the steps 9 steps high?
Is there a pattern that can help you solve the problem?
Hi,
ReplyDeleteI think that the answer is 45.
My strategy was to add them up.
1+2=3
3+3=6
6+4=10
10+5=15
15+6=21
21+7=28
28+8=36
36+9=45
From Alex
P.S I think this is a great blog! It gives me something to think about when I get home on a Monday.
The answer is 45. I worked it out by drawing a picture of the steps and adding all the steps together by using tidy tens. Then I added the five that was left over on. To work out the number of blocks needed for any number of steps you have to add up one plus two plus three and so on until you get to the number of steps you need. From Kate.
ReplyDeleteTo solve this problem I drew a picture to show how many steps there were to get to 9 steps high. Then I counted all the blocks up using tidy numbers. I counted them like this. 9+1=10 8+2=10 7+3=10 6+4=10 and there was only 5 left. Then I added them all up to make 45!
ReplyDeleteSo 45 blocks are needed to make the steps 9 steps high.
FROM MIA!
I think that each step gets an extra cube each time which means that the question is 1+2+3+4+5+6+7+8+9=45
ReplyDeleteFrom Billie
Hi,
ReplyDeleteA pattern that can help you is this:
Get the number of steps in the staircase (A).
Multiply it by the number after the number of steps (A+1).
Divide them by 2
So the rule is Ax(A+1)/2
Example for if you have 9 steps: 9x10/2=45.
From Alex.