狼姥姥每日一题 - 数学 Problem solving （25-6-2012）:D :D

狼姥姥

[tr][td]本帖最后由 狼姥姥 于 2012-5-27 20:24 编辑

经常有些朋友问些关于小龙女做些什么数学题。这几天想了一下，有个提议，我把小龙女做过的problem solving放坛子上，也希望各位家长把你们孩子的题也放上来，互相交流，互相换题

我知道坛子里有很多教数学的高手，希望大家多多赐教，多多参与，把答案，解题过程等放上来，互相参考呗

题也不分什么容易啊简单啊，随机抽放。

一直以来我都认为多做一些数学题对大脑发育有很大帮助，而且数学是所有理科的基础，通过这个平台，也可以让你的孩子，每天做一题，来提高他们的数学运算能力和思考能力，孩子还小的家长，现在就可以热热身。 声明，不可以用方程来解。

20.05.2012

老师出了30道问题，答对一道给5分，打错一道扣10分。小龙女 （）得了90分，问她错了几道题。


[/21.05.2012

a truck carries newspapers.
when the truck is half full of newspapers the truck has a mass of 1762kg. when it is a quarter full the truck has a mass of 1426kg.
what is the mass of the truck when it is full of newspaper?
一货车运报纸
货车装满一半的时候，体重为1762kg. 货车装了1/4,体重1426kg. 请问货车装满报纸是多少公斤？



]22.05.2012

Uma has cubes that come in two different sizes. She makes a stack of 7 small cubes and a stack of 5 large cubes. The two stacks are the same height.

A  large cube is 6 millimetres taller than a small cube.

What is the height of one stack, in millimetres?

23.05.2012
a number has 3 digits. when it is divided by 6 or 7 it leaves a remainder of 1. when it is divided by 8 or 11, it leaves a remainder of 7. what is the largest such number?



24.05.2012

小龙女有24件衣服，其中14件没有口袋，15件短袖，有6件长袖带口袋，问小龙女有几件不带口袋的短袖。


26.05.2012

in a school of 600 students, 320 study korean, 270 study thai and 110 study german.

there are 150 students who study only two languages: 60 students study korean and thai, 50 students study thai and german, and 40 students study german and korean.

at most how many students study all three language?


]27-05-12
马大姐正在攒钱买一件东西。她只有一块和两块钱硬币。她的两块钱的硬币数量是一块钱的两倍。如果她有70元钱，她有多少枚一块钱硬币？
Revenge is sweet!!!!

28.05.12
小龙女can make 2 pies in 3 minutes
马大姐can make 3 pies in 2 minutes

]how many pies can they make together in an hour?
(yes jo, revenge is sweet..... SHB rulz....anyday....even when it comes to making pies)



29.05.12
A group of friends shared 108 chocolates equally, the number of chocolates each friend got was three more than the number of friends. How many chocolates did each friend get?



30-05-12
马大姐is walking up a set of stairs. She stops when she is 5/8 way through. Then she walked another nine steps. This time she is 3/4 way up. How many steps are there in total on the stairs?

31.05.12
at the local swimming pool it costs $1 to hire a towe and 60c to hire a deckchair. rebecca hired some of each and spent $5.80 altogether. how many towels and deckchairs did she hire?

01-06-12
One morning Luisa Noor and Manling counted their pencils. They found that Luisa had three times the number pencils that Manling had Noor had twice the number that Manling had.
By the end of the day,Noor had lost four pencils,and had 34 pencils left.
How many pencils did Luisa have on that morning?

05-06-12
A father and son have the same birthday.In 2001 the father was 42 and the son was 11.In what year will the father be exactly twice as old as his son?

8-6-12
A clock is correctly set at three pm. It looses two minutes every hour. What will the clock read when the correct time is 10pm the next day?

09-06-12
How many two-digit numbers are there in which the tens digit is greater then the ones digit?

狼姥姥

25-6-12
when jenny was sent to get change for the parking metre, she changed a dollar into 16 coins, consisting of 5cent and 10cent pieces. how many coins of each kind were in the change?

good luck!!! get your minds ticking!

狼姥姥

21-6-12

6xx5 is a multiple of 9. the two "x' represent the same digit. what does "x" represent?

springbok

狼姥姥 发表于 2012-6-20 19:31
20-6-12
Two questions today!!!!

Answer:
1.  80 + 106 + 94 = 280 (all stamps counted twice together),  so: 280 / 2 = 140 stamps

2.  20cents   10 cents
        1              7   ( 90 cents)
        2              6    ( $1.00)
        3              5    ($1.10)
        4              4    ( $ 1.20)
        5              3   ( $ 1.30)

SO:  six 10cent coins.

狼姥姥

20-6-12
Two questions today!!!!

Annie, Blake and Cara collects stamps. Annie and Blake has 80 stamps together. Annie and Cara has 106 stamps altogether. Blake and Cara has 94 stamps altogether. How many stamps does Annie Blake And Cara have altogether.

Bob took eight 10cent and 20cent coins from a piggy bank. He had $1 altogether, how many 10cent coins did bpBob pick out.

直面异议

。

直面异议

这种题对绝大多数的孩子好无意义.多花点时间，学语文。

狼姥姥

18-6-12

If a bottle and it's cork costs $1.10 and the bottle costs $1 more than the cork, how much doesnthe cork cost?

springbok

狼姥姥 发表于 2012-6-17 19:14
17-06-12
Tennis balls are usually sold in a shop at three for four dollars. If the price is changed ...

Price 1: $3/4 = $0.75/ball        P2 (Saturday): $4/5 = $0.80/ball

New cost: 12 x $ 0.80 = $ 9.60

Usual cost: 12 x $0.75 = $ 9.00

difference : $0.60. New cost is 60cents more than the usual cost.

springbok

狼姥姥 发表于 2012-6-12 21:53
A transistor radio company can only package it's radios in boxes of 6 and boxes 8.what is the least  ...

pack box with 8 first but the remainder from 44 must can divide by 6.

answer : 4 boxes with 8, 2 boxes with 6.  (6boxes)

springbok

狼姥姥 发表于 2012-6-11 22:18
The average of four numbers is 11.If 6,a fifth number is added to the four numbers,what is the avera ...

total = 4x11 = 44

44+6 = 50/5 =10 (average)

springbok

狼姥姥 发表于 2012-6-10 22:43
10-06-12
When added together three whole numbers give a total of 10.When multiplied together the sa ...

factors of 30,

1,2,3,5,6,10,15,30

answer: 2,3,5

狼姥姥

17-06-12
Tennis balls are usually sold in a shop at three for four dollars. If the price is changed one saturday to four for five dollars. Will the new cost for twelve balls be more or less than the usual cost for 12 balls, and by how much.

狼姥姥

A transistor radio company can only package it's radios in boxes of 6 and boxes 8.what is the least number of full boxes needed to package 44 radios?

狼姥姥

The average of four numbers is 11.If 6,a fifth number is added to the four numbers,what is the average of the five numbers?

马龙

对不起，忙着解答呢。

狼姥姥

10-06-12
When added together three whole numbers give a total of 10.When multiplied together the same numbers give a product of 30.What are the three numbers?

狼姥姥

这个坛子人气好像不太旺。

狼姥姥

狼姥姥

放完假回来继续更新。

狼姥姥

狼姥姥

月明 发表于 2012-5-30 22:49
请问你小孩是在哪个校区读书？因为我小孩上六年级了，从来没有带回来这种程度的数学题，难道不同学校的教 ...

Mt Roskill 中学，有些题都是学校把数学好的学生选出来，由校长或数学组组长单独授课，有些题是参加数学竟赛留下來的。还有就是搜刮来的，因为我家小龙女喜欢做这种题。

狼姥姥

love_3_month 发表于 2012-5-31 07:30
马大姐is walking up a set of stairs. She stops when she is 5/8 way through. Then she walked another  ...

答题过程真详细。

love_3_month

马大姐is walking up a set of stairs. She stops when she is 5/8 way through. Then she walked another nine steps. This time she is 3/4 way up. How many steps are there in total on the stairs?

1.
5/8 变成3/4 (=6/8) 就是增加了1/8, 同时等于9steps
so there are 9*8 = 72 steps.

2. 3/4 *X - 5/8 * X = 9,
X = 72

月明

狼姥姥 发表于 2012-5-21 08:49
因为是给小学生做的，他们还没有学到方程，当时女儿把题拿回来时说，这道题是老师给的，女儿只猜出答案， ...

请问你小孩是在哪个校区读书？因为我小孩上六年级了，从来没有带回来这种程度的数学题，难道不同学校的教育程度差别有这么大吗？

狼姥姥

love_3_month 发表于 2012-5-30 14:42
哦, 这样啊

如果学校没有教, 但自己在家里教, 然后考试的时候这么用, 会扣分吗?

其实你说的这种情况，我家马大姐和小龙女都遇到过，我是教了她们俩方程，所以很快给出答案。不会扣分，可是，在学方程之前怎么办，总不能等学完方程再做吧。所以要教给小孩算术解法，然后再教方程。

cindyppz

love_3_month 发表于 2012-5-30 14:42
哦, 这样啊

如果学校没有教, 但自己在家里教, 然后考试的时候这么用, 会扣分吗?

考试一般是不会给这种题的。。。。

love_3_month

哦, 这样啊

如果学校没有教, 但自己在家里教, 然后考试的时候这么用, 会扣分吗?

就好象老师问, 1+2+3+4+5+....+100=? 他可能希望学生一个个的加, 但如果学生写出 = (1+100)*100/2 = 5050, 可以吗?

狼姥姥

love_3_month 发表于 2012-5-30 09:50
A group of friends shared 108 chocolates equally, the number of chocolates each friend got was three ...

用第一种确实简单、直观，但小学生还没有学到方程，所以只能用一些列举法，才能让学生明白，尤其是纽西兰的学生。

love_3_month

A group of friends shared 108 chocolates equally, the number of chocolates each friend got was three more than the number of friends. How many chocolates did each friend get?.

就是用非方程式来解需要方程式的题目啊

1.
方程式, X*(X+3) = 108
X*X + 3X -108 = 0
(X+12)*(X-9) =0
X=9 (X =-12 不成立)

2. 非方程式
108 分解 质因数= 2*2*3*3*3
拆成两组, 乘积 差3
2*2*3 vs 3*3 = 12 vs 9.

其实是一个道理, 因为解方程就是分解质因数.......前者更直观一点.