https://www.education.com/games/first-grade/math/
https://www.abcya.com/first_grade_computers.htm#numbers-cat
http://www.bbc.co.uk/schools/laac/numbers/chi.shtml
http://www.arcademicskillbuilders.com/games/alien/alien.html
- http://www.harcourtschool.com/activity/numberline1_5_04/
Working with number lines
http://www.playkidsgames.com/games/mathfact/default.htm
- http://www.primarygames.com/add_up/start.htm
Click on start.
Basic Subtraction: Practice Subtracting
- http://www.aaamath.com/B/g1_26bx2.htm#section2
Basic Subtraction Facts Lesson: Count and subtract triangles, circles, squares