Try this:
https://www.khanacademy.org/math/arithmetic/arith-decimals/arith-review-decimals-to-fractions/e/converting_fractions_to_decimals_0.5
TOOLS
http://www.didax.com/apps/base-ten-blocks/
https://www.coolmath4kids.com/manipulatives/base-ten-blocks
Properties of Addition
https://www.aaamath.com/pro74ax2.htm
https://www.khanacademy.org/math/pre-algebra/pre-algebra-arith-prop/pre-algebra-arithmetic-properties/a/properties-of-addition
https://www.coolmath.com/prealgebra/06-properties/01-properties-commutative-addition-01
https://www.coolmath.com/prealgebra/06-properties/05-properties-distributive-01
https://www.khanacademy.org/math/cc-fifth-grade-math/imp-addition-and-subtraction-3/imp-adding-decimals-intro/v/estimating-adding-decimals
https://www.splashmath.com/decimal-games (just decline signing up)
https://www.turtlediary.com/games/decimals.html
http://www.kidsmathgamesonline.com/numbers/decimals.html
http://www.math-play.com/decimal-math-games.html