Kids Math Books - Math Books for Kids

Why parents can't do maths today

noreply@blogger.com (Nguyen Thi Lan Phuong) — Tue, 05 Jul 2011 01:36:58 PDT

Long division and long multiplication have been replaced in schools by chunking and gridding. While the new methods are meant to make maths easier, parents have been left scratching their heads,...

Patriots vs. Redcoats: An Outdoor Social Studies Game

noreply@blogger.com (Nguyen Thi Lan Phuong) — Tue, 21 Jun 2011 21:30:08 PDT

This outdoor game, a modification of "Capture the Flag", uses ball, baskets, and foam to re-enact the fight between the Redcoats and the Patriots in Massachusetts in 1775.Can your foam-armed...

Create a Two-Sided Opposites Painting

noreply@blogger.com (Nguyen Thi Lan Phuong) — Tue, 21 Jun 2011 21:27:11 PDT

Create a colorful painting—twice! Transform a single sheet of card stock into a double-sided painting of opposites: on one side, a bright daytime landscape, on the other, a dusky evening scene. Not...

2 Grade Math Facts Secret Codes Actvities

noreply@blogger.com (Nguyen Thi Lan Phuong) — Tue, 21 Jun 2011 21:30:23 PDT

When it comes to those basic math facts, there's nothing like practice, practice, practice. But making them interesting is quite another matter. Here's an irresistible activity you can use with...

42nd IMO 2001 shortlisted problems and solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Sun, 13 Feb 2011 05:24:00 PST

Algebra A1. Let T be the set of all triples (a, b, c) where a, b, c are non-negative integers. Find all real-valued functions f on T such that f(a, b, c) = 0 if any of a, b, c are zero and f(a, b,...

41st IMO 2000 shortlisted problems and solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Sun, 13 Feb 2011 01:24:20 PST

Algebra A2. a, b, c are positive integers such that b > 2a, c > 2b. Show that there is a real k such that the fractional parts of ka, kb, kc all exceed 1/3 and do not exceed 2/3. ...

40th IMO 1999 shortlisted problems and solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Sun, 13 Feb 2011 01:11:28 PST

AlgebraA2. The numbers 1 to n2 are arranged in the squares of an n x n board (1 per square). There are n2 (n-1) pairs of numbers in the same row or column. For each such pair take the larger...

39th IMO 1998 shortlisted Problems and Solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Fri, 11 Feb 2011 02:20:15 PST

Algebra A1. x1, x2, ... , xn are positive reals with sum less than 1. Show that nn+1x1x2 ... xn(1 - x1 - ... - xn) ≤ (x1 + x2 + ... + xn)(1 - x1)(1 - x2) ... (1 - xn). A2. x1, x2, ... ,...

38th IMO 1997 shortlisted Problems and Solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Fri, 11 Feb 2011 02:07:25 PST

2. The sequences Rn are defined as follows. R1 = (1). If Rn = (a1, a2, ... , am), then Rn+1 = (1, 2, ... , a1, 1, 2, ... , a2, 1, 2, ... , 1, 2, ... , am, n+1). For example, R2 = (1, 2), R3 = (1, 1,...

37th IMO 1996 shortlisted Problems and Solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Thu, 10 Feb 2011 03:01:33 PST

1. x, y, z are positive real numbers with product 1. Show that xy/(x5 + xy + y5) + yz/(y5 + yz + z5) + zx/(z5 + zx + x5) ≤ 1. When does equality occur? 2. x1 ≥ x2 ≥ ... ≥ xn are real...

36th IMO 1995 shortlisted Problems Solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Wed, 09 Feb 2011 02:24:20 PST

AlgebraA2. a, b, c are integers such that a ≥ 0, b ≥ 0, ab ≥ c2. Show that for some n we can find integers x1, x2, ... , xn, y1, y2, ... , yn such that x12 + x22 + ... + xn2 = a, y12 + y22 + ... +...

35th IMO 1994 shortlisted Problems and Solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Wed, 09 Feb 2011 02:25:06 PST

Algebra A1. The sequence x0, x1, x2, ... is defined by x0 = 1994, xn+1 = xn2/(xn + 1). Show that [xn ] = 1994 - n for 0 ≤ n ≤ 998. A4. h and k are reals. Find all real-valued functions...

34th IMO 1993 shortlisted Problems and Solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Wed, 09 Feb 2011 02:25:44 PST

1. Show that there is a finite set of points in the plane such that for any point P in the set we can find 1993 points in the set a distance 1 from P. 2. ABC is a triangle with...

33rd IMO 1992 shortlisted Problems and Solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Wed, 09 Feb 2011 02:25:36 PST

1. m is a positive integer. If there are two coprime integers a, b such that a divides m + b2 and b divides m + a2, show that we can also find two such coprime integers with the additional...

32nd IMO 1991 shortlisted Problems and Solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Wed, 09 Feb 2011 02:24:43 PST

32nd IMO 1990 shortlisted Problems and Solutions 1. ABC is a triangle and P an interior point. Let the feet of the perpendiculars from P to AC, BC be P1, P2 respectively, and let the feet of the...

31st IMO 1990 shortlisted Problems and Solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Thu, 27 Jan 2011 01:43:01 PST

1. Is there a positive integer which can be written as the sum of 1990 consecutive positive integers and which can be written as a sum of two or more consecutive positive integers in just 1990...

30th IMO 1989 shortlisted Problems and Solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Thu, 27 Jan 2011 01:39:58 PST

1. Ali Baba has a rectangular piece of carpet. He finds that if he lays if flat on the floor of either of his storerooms then each corner of the carpet touches a different wall of the room. He...

29th IMO 1988 shortlisted Problems & Solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Thu, 27 Jan 2011 01:28:10 PST

1. The sequence a0, a1, a2, ... is defined by a0 = 0, a1 = 1, an+2 = 2an+1 + an. Show that 2k divides an iff 2k divides n. 2. Find the number of odd coefficients of the polynomial (x2 +...

26th IMO 1985 shortlisted problems & Solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Thu, 27 Jan 2011 01:19:30 PST

1. Show that if n is a positive integer and a and b are integers, then n! divides a(a + b)(a + 2b) ... (a + (n-1)b) bn-1. 2. A convex quadrilateral ABCD is inscribed in a circle radius...

24th IMO 1983 shortlisted problems & Solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Thu, 27 Jan 2011 01:10:50 PST

1. 1983 cities are served by ten airlines. All services are both ways. There is a direct service between any two cities. Show that at least one of the airlines can offer a round trip with an odd ...

1st - 9th IMO 1959-67 shortlisted problems

noreply@blogger.com (Nguyen Thi Lan Phuong) — Thu, 27 Jan 2011 01:04:33 PST

1. Given n > 3 points in the plane, no 3 collinear, show that there is a circle through 3 of the points such that none of the points lies inside the circle. 2. Given n positive reals...

19th Chinese Mathematical Olympiad 2004 Problems & Solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Wed, 26 Jan 2011 22:56:19 PST

A1. ABCD is a quadrilateral. E, F, G, H are points on AB, BC, CD, DA respectively such that (AE/EB)(BF/FC)(CG/GD)(DH/HA) = 1. The lines through A parallel to HE, through B parallel to EF, through...

17th Chinese Mathematical Olympiad 2002 Problems & Solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Wed, 26 Jan 2011 22:51:55 PST

A1. ABC is a triangle. What conditions must angles A, B, C satisfy if angle B < angle C and we can find X on AB and Y on AC such that BX = CY and angle BZX = angle CZY, where AZ is the angle ...

16th Chinese Mathematical Olympiad 2001 Problems & Solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Wed, 26 Jan 2011 22:51:27 PST

A1. ABCD is a cyclic quadrilateral. The center of the circumcircle lies inside ABCD. The shortest side has length √(4 - t2) and the longest side has length t, where √2 < t < 2. The tangents ...

15th Chinese Mathematical Olympiad 2000 Problems & Solutions

noreply@blogger.com (Nguyen Thi Lan Phuong) — Wed, 26 Jan 2011 22:51:14 PST

A1. ABC is a triangle. As usual |BC| = a, |CA| = b, |AB| = c, the circumradius is R and the inradius is r. We are given that a ≤ b ≤ c. For which values of the angle C is a + b - 2(r + R) ...