Form 1 Maths (Estimation)
2010-12-17 3:04 am
Mandy wants to buy a $200 doll after theChinese New Year holiday. She receives five red-pockets, with sum of money $42,$43, $49, $31 and $36 respectively. By using rounding down, estimate if she has sufficient money tobuy that doll. Explain briefly. I don't know how to explain! By rounding down to the nearest $10, totalsum of money » $(40 + 40 + 40 + 30 + 30) = $180,which is less than $200. But in this case, shall I write (1) There is no conclusion, becauseactually sum of money = $(42 + 43 + 49 + 31 + 36) = $201Or, (2) Mandy has insufficient money by usingthe round-down strategy (only).Thank you.
回答 (2)
2010-12-17 4:47 am
✔ 最佳答案
to know that are you correct first:case one(Rounding off(A):corr. to the nearest 10$ after sum up,or front-end method after sum up(???))
42+43+49+31+36=201$=200$
case 2(Rounding off (B):corr. to the nearest 10$ before sum up)
42+43+49+31+36
=40*2+50+30+40
=200$
case 3(front-end method before sum up)
42»40
43»40
49»40
31»30
36»30
40+40+40+30+30=180$
case 4(clustering)
estimate 42+43+49+31+36
let us focus on 40
42+43+49+31+36
=40*5
=200$
according to the cases,only case 3 can't expected
so I think tat u are right
I prefer you to read this:
http://www.takwing.idv.hk/mathroom/junior/form1/06_estimate.htm
that's it
2010-12-17 3:18 am
your answer is alright~
this question is definitly a bad question
with unsuitable values set by the teacher~
this question is definitly a bad question
with unsuitable values set by the teacher~
參考: me~=]
收錄日期: 2021-04-23 20:47:59
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20101216000051KK00745