This shoe fits very small.  Go up at least one size from your street size 

Slip-on Wonder Jazz Shoe

Allure the crowd in the Wonder Jazz. The top feature is the two staged internal insert that improves comfort, cushioning and traction. This gives the dancer optimal control for sudden stops in a fast, competition-style routine. Low profile elasticized top line reflects the contours of the foot to create a stylized fit. Folded stitched edge on the upper is for strength while also creating a sleeker appearance overall.

Product Features:

• Slip-on, split-sole
• Burro leather with neoprene stretch insert
• Daplex arch hugging stretch textile
• 100% microfiber lining for breathability
• EVA sole and heel
• Elasticized, lower top line reflects contour of foot and gives a glove-like fit from heel to toe
• Two staged special internal insert
• Low sides
• Pleated toe for ballet fit
• Women: Begin with street shoe size. Men: Begin 2 sizes up from street shoe size.
• This shoe tends to run narrow