#### A Math Forum Project

Math Forum || Problems of the Week || Student Center

This Web page is intended to record solutions submitted by students in grades three through twelve. Student solutions were submitted January 1, 1999 through February 1,1999. Submissions for missing numbers can still be submitted using the Web form.

Rules: use the digits in the year 1999 and the operations of +, -, x, ÷, sqrt (square root), ^ (raise to a power), and ! (factorial), along with grouping symbols, to write expressions for the counting numbers 1 through 100. Please read and follow the rules carefully.

Teachers may print out worksheets for students to record their findings, or print sheets of manipulatives for students to use.

## STUDENT SOLUTIONS 81 to 90

 Solution Name Grade School 81 (sqrt9*9)*sqrt9*1 Michael Falls 6 Raymond Park Middle School 81 (1^9)(9)(9) Lisa Gardner 3 Boyette Springs ES 81 (9 - 1) x 9 + 9 Lisa Jackson 4 Cheat Lake Elementary 81 sqrt9xsqrt9x9x1 Mireille Martineau 7 St.Jude School, Brooklyn,NY 81 (sqrt9*sqrt9)*9*1 David Moudy 7 Raymond Park Middle School 81 (1+9)9-9 Tom Muller 8 Reading-Fleming Middle School 81 9x9x1^9 Victoria 5 James River Elementary 81 (1+9)*9-9 Jessica Erwin/Crystal Muguerza 7 T.A. Howard Middle School 82 1+(9^sqrt9)/9 Wendy Cheung 10 The Bishop Strachan School 82 sqrt9xsqrt9x9+1 Elizabeth Fahey 7 St.Jude School, Brooklyn, NY 82 (sqrt9*9)*sqrt9+1 Michael Falls 6 Raymond Park Middle School 82 1^9 +9x9 Lisa Gardner 3 Boyette Springs ES 82 (sqrt9*sqrt9*9+1 David Moudy 7 Raymond Park Middle School 82 1+sqrt9*9*sqrt9 Jessica Erwin/Crystal Muguerza 7 T.A. Howard Middle School 82 9x9+1^9 Victoria 5 James River Elementary 83 (9x9+sqrt9)-1 Tony Drake 6 Raymond Park Middle School 83 (9*9)+(sqrt9-1) Michael Falls 6 Raymond Park Middle School 83 (-1 + sqrt9) + (9)(9) Lisa Gardner 3 Boyette Springs ES 83 ( 9x9 ) + sqrt 9 - 1 Jessica Hammond 4 Cheat Lake Elementary 83 9x9+sqrt9-1 Tatiana Phanor 8 St.Jude School, Brooklyn, NY 83 9 x 9 + sqrt(9) - 1 J. D. Wilson 7 Wilson Central Junior High, West Lawn, PA 83 -1+(9*9)+sqrt9 Jessica Erwin/Crystal Muguerza 7 T.A. Howard Middle School 84 (9*9)+(sqrt9*1) Michael Falls 6 Raymond Park Middle School 84 (1 +9)(9) -(sqrt9)! Lisa Gardner 3 Boyette Springs ES 84 ((9x9) + sqrt 9) x 1 Jessica Hammond 4 Cheat Lake Elementary 84 9x9+sqrt9x1 Tatiana Phanor 8 St.Jude School,Brooklyn, NY 84 (1*sqrt9)+(9*9) Chris Waid 8 RFMS 84 (1*sqrt9)+(9*9) Jessica Erwin/Crystal Muguerza 7 T.A. Howard Middle School 85 (9*9)+(sqrt9+1) Michael Falls 6 Raymond Park Middle School 85 (1 + sqrt9) + (9)(9) Lisa Gardner 3 Boyette Springs ES 85 9x9+sqrt9+1 Michelle Goldwyn 8 Reading-Fleming Middle School 85 ( ( 9x9 ) + sqrt 9 ) + 1 Jessica Hammond 4 Cheat Lake Elementary 85 9x9+sqrt9+1 Tatiana Phanor 8 St.Jude School, Brooklyn, NY 85 (1+sqrt9)+(9*9) Chris Waid 8 RFMS 85 1+(9*9)+sqrt9 Jessica Erwin/Crystal Muguerza 7 T.A. Howard Middle School 86 (9*9)+(sqrt9!-1) Michael Falls 6 Raymond Park Middle School 86 (-1 + (sqrt9)!+ (9)(9) Lisa Gardner 3 Boyette Springs ES 86 9x9+(sqrt9)!-1 Daniel Natale 7 St.Jude School, Brooklyn, NY 86 (-1+sqrt9!)+(9*9) Jessica Erwin/Crystal Muguerza 7 T.A. Howard Middle School 87 (9+1)x9-sqr9 Sarah Bocik 6 Raymond Park Middle School 87 (1+9)x9-(sqrt9) Wendy Cheung 10 The Bishop Strachan School 87 (9*9)+(sqrt9!*1) Michael Falls 6 Raymond Park Middle School 87 (1+9)(9) -sqrt9 Lisa Gardner 3 Boyette Springs ES 87 (9x9)+(sqrt9)!x1 Daniel Natale 7 St.Jude School, Brooklyn, NY 87 1*(9*9)+sqrt9! Jessica Erwin/Crystal Muguerza 7 T.A. Howard Middle School 88 1+9x9+((sqrt9)!) Wendy Cheung 10 The Bishop Strachan School 88 (9*9)+(sqrt9!+1) Michael Falls 6 Raymond Park Middle School 88 1+ (sqrt9)! +(9)(9) Lisa Gardner 3 Boyette Springs ES 88 9x9+sqrt9!+1 Michelle Goldwyn 8 Reading-Fleming Middle School 88 (9*9)+(sqrt9)!+1 David Moudy 7 Raymond Park Middle School 88 9x9+(sqrt9)!+1 Daniel Natale 7 St.Jude School, Brooklyn, NY 88 (1+sqrt9!)+(9*9) Jessica Erwin/Crystal Muguerza 7 T.A. Howard Middle School 89 -1+9+9*9=89 Jared Baker 8 Reading-Fleming middle school 89 (9*9)+(9-1) Michael Falls 6 Raymond Park Middle School 89 (-1) +9 +(9)(9) Lisa Gardner 3 Boyette Springs ES 89 -1+9x9+9 Michelle Goldwyn 8 Reading-Fleming Middle School 89 ((9 x 9) + 9) - 1 Lisa Jackson 4 Cheat Lake Elementary 89 (9 x 9) + 9 - 1 Will Morrison 4 Cheat Lake Elementary 89 (9*9)+9-1 David Moudy 7 Raymond Park Middle School 89 9x9+9-1 Toni-Ann Syncon 8 St.Jude School, Brooklyn, NY 89 9x9+9-1 Chris Whitley 6 Raymond Park Middle School 89 (-1+9)+(9*9) Jessica Erwin/Crystal Muguerza 7 T.A. Howard Middle School 89 9*9+9-1 Math Group 11 8 Ashford School 90 (9*9)+(9*1) Michael Falls 6 Raymond Park Middle School 90 1x9+9x9 Chelsea Flaum 10 Gulf Coast High School 90 (1)(9) +(9)(9) Lisa Gardner 3 Boyette Springs ES 90 (9x9)x1+9 Sara Gobble 6 Raymond Park Middle School 90 1x9x9+9 Michelle Goldwyn 8 Reading-Fleming Middle School 90 ((9 x 9) + 9) x 1 Lisa Jackson 4 Cheat Lake Elementary 90 (9 x 9 ) + (9 x 1) Will Morrison 4 Cheat Lake Elementary 90 (9*9)+9*1 David Moudy 7 Raymond Park Middle School 90 1*9*9+9 Chris Scanlan 8 Reading Fleming Middle School 90 (1+9)sqrt9*sqrt9 Eric Stec 8 Reading Fleming Middle School 90 9x9+9x1 Toni-Ann Syncon 8 St.Jude School, Brooklyn, NY 90 (1^9+9)*9 Chris Waid 8 RFMS 90 9*9+9*1 mathgroup10 8 Ashford School 90 9*9+9*1 Math Group 11 8 Ashford School 90 (1*9)+(9*9) Jessica Erwin/Crystal Muguerza 7 T.A. Howard Middle School

Please notify Judy Ann Brown of any errors.

The Math Forum ** 22 December 1998