8th Grade Math Contest!

Real Numbers and Scientific Notation

100

What is the number 1,000,000,000 written as in scientific notation?

1 x 10^9

200

What is the number 0.000000018 written as in scientific notation? (Remember moving decimals effects the sign of the exponent!)

1.8 x 10^-8

Proportional and Nonproportional Relationships

100

What is the y-intercept in this equation?

Y = -4x + 6

B = 6

200

Given this Equation - 

Y = -17x + 3.5

Will the line be slopping up or down and why? 

The line will slope down because the slope -17 is negative. 

Solving Equations

100

Solve for X in this equation:  X^2 = 121

(Remember how squares can have multiple answers!)

X = 11 and -11

200

Given these two points on a line -

p₁(2, 2)        and          P₂(4, 8)

Calculate the slope using Slope Formula

m = (Y₂ - Y₁) / (X₂ - X₁)

m = (8 - 2) / (4 - 2)

m = 6/2

m = 3

Word Problems

100

The SBC is making Valentines Day grams for our school! They will use 25 lollypops per class (c) and a total of 50 pieces of paper. What would the equation from this scenario be in -

Y = mx + b form?

Y = 25c + 50

200

Solve this System of Equations by substitution:

X + Y = -9

      Y = 2x

X + Y = -9

      Y = 2x

X + (2x) = -9

3x = -9

X = -3