Math Puzzle: S and K both wrote down a number with a 7. Each number looks like ".xxx"

[Barbados]

Math Puzzle: S and K both wrote down a number with a 7. Each number looks like ".xxx"

S and K both wrote down a number with a 7. Each number looks like ".xxx". S's 7 is 1/100th "of" K's 7. Child's teacher is saying D is correct. Teacher is also saying S's 7 is less than K's 7, but D is inverse to this statement unless referring directly to the 7 itself. Daughter took paper back to school, so I can't post verbatim.

S K
A. .872 .271
B. .187 .871
C. .478 .754
D. .837 .738


Thanks for any help.

 

[stapel]

S and K both wrote down a number with a 7. Each number looks like ".xxx". S's 7 is 1/100th "of" K's 7. Child's teacher is saying D is correct. Teacher is also saying S's 7 is less than K's 7, but D is inverse to this statement unless referring directly to the 7 itself. Daughter took paper back to school, so I can't post verbatim.

S K
A. .872 .271
B. .187 .871
C. .478 .754
D. .837 .738

What answer did you get? And how are you getting that 0.007 = 7/1,000 is "larger" than 0.7 = 7/10?

Please reply showing your work and reasoning, so we can try to figure out where things are going wrong. Thank you!

 

[Barbados]

Thanks for the response Stapel.

My Daughter brought home a worksheet for the week. Her class did this problem together as an example and provided that D is correct. You can spacebar the S and K over a little to align S and K to their respective columns.

I am looking at the problem myself and do not see either ("of" was the operative word) adding or taking away from a 7 in the 100ths position (.xXx) would be "of" (more or less) and could vary to .7xx if D is the correct answer per the teacher's answer provided to the students.

I am opting for B because the 8 in S's number is .08 and the 7 in K's number (.871). However, the way I have interpreted the facts are both have a 7 and the deviation in the 7s is 1/100th. Will verbatim this as soon as she gets home and I can lay my hands on that paper.

I did write this down on the easel, but I might be missing some facts now.

Attaches is what I wrote down last night.

 

[Barbados]

OK...I see D does not break the less than rule. , but I don't see how .837 7 thousandths in S's response (still referring to answer choice D) is only 1/100th "of" (variation) .738.
OK, hope to show what I am doing wrong a little better now.

For example:
.837 -.01= .827 (since the operative word was "of" (variance)) or .837 +.01 = .847. Neither of which are anywhere near the .738 provided in answer D.

 

[Otis]

S's 7 is 1/100th "of" K's 7.

Teacher is also saying S's 7 is less than K's 7, but D is inverse to this statement unless referring directly to the 7 itself.

Yes, the teacher's statement refers only to the value of the digit 7 in each number.

Were the teacher to have made a statement comparing the numbers 0.837 and 0.738, then they would have had to say, "K's number is less than S's number".

1/100th of 0.7 is 0.007

 

[Barbados]

1/100th of 0.7 is 0.007

Thank you guys for helping me understand. Now I must patiently help her solve the problem this evening.

 

[Ishuda]

S and K both wrote down a number with a 7. Each number looks like ".xxx". S's 7 is 1/100th "of" K's 7. Child's teacher is saying D is correct. Teacher is also saying S's 7 is less than K's 7, but D is inverse to this statement unless referring directly to the 7 itself. Daughter took paper back to school, so I can't post verbatim.

S K
A. .872 .271
B. .187 .871
C. .478 .754
D. .837 .738


Thanks for any help.

Let S be S's 7 and K be K's 7. Interpreting 'S's 7 is 1/100th of K's" seems to me to say "K/S = K/[(1/100)K] = 100". So

A: S is 0.07=7*10^-2, K is 0.07=7*10^-2 ===> K/S = 1

B: S is 0.007=7*10^-3, K is 0.07=7*10^-2 ===> K/S = 10

C: S is 0.07=7*10^-2, K is 0.7=7*10^-1 ===> K/S = 10

D: S is 0.007=7*10^-3, K is 0.7=7*10^-1 ===> K/S = 100

So D is correct.

From teacher: "S's 7 is less than K's 7". Well yes, since if it were the other way around, K/S would be less that 1, i.e.
S > K ===> 100 > 1 > K/S which is wrong
S < K ===> 100 = K/S > 1 which is correct

 

[Barbados]

My problem was that I was taking S's 7 and adding 1/100 (.01) to it and not 1/100 of K's .7. We got through the rest of the problems and had a bit of fun. I really do not understand the way the school is approaching these concepts at times; not at all intuitive to me. Her class is also using number charts/lines to show their work for rounding. She did pay more attention in class yesterday. Got to get her going this school year.

Thanks for the help everyone. Will add another puzzle.