Khan Academy

Sum of integers challenge (K-A)

Sums of consecutive integers (K-A)

Substitution method review (systems of equations) (K-A)

Systems of equations with substitution (K-A)

Systems of equations with substitution: -3x-4y=-2 & y=2x-5 (K-A)

Systems of equations with substitution: 2y=x+7 & x=y-4 (K-A)

Systems of equations with substitution: 9x+3y=15 & y-x=5 (K-A)

Systems of equations with substitution: y=-1/4x+100 & y=-1/4x+120 (K-A)

Systems of equations with substitution: y=-5x+8 & 10x+2y=-2 (K-A)

Systems of equations with substitution: y=4x-17.5 & y+2x=6.5 (K-A)

Intro to addition (K-A)

Intro to subtraction (K-A)

Making 5 (K-A)

Adding to 10 (K-A)

Getting to 10 by filling boxes (K-A)

Add and subtract: pieces of fruit (K-A)

Addition and subtraction within 10 (K-A)

Addition word problems within 10 (K-A)

Subtraction word problems within 10 (K-A)

Counting in order (K-A)

Counting with small numbers (K-A)

Missing numbers between 0 and 120-video (K-A)

Number grid-video (K-A)

Counting in pictures (K-A)

Counting objects 1 (K-A)