Translation: Hay cien brujas en escobas en el cielo.
To make it a little clearer that the witches are mounted atop the brooms than that they may be inside of the brooms (the Spanish is ambiguous), you could say "Hay cien brujas montadas en escobas en el cielo." which translates to "There are 100 witches riding brooms in the sky."
Witches of the middle ages were more often than not thought to be women, and a disproportionate number of those condemned as witches were in fact female. Women of the time did the work of running the household and part of that included the cleaning. Brooms were part and parcel of their "equipment" so when looking for "proof" that a woman was a witch, the accusers could point to the broom and say, "There is proof". This dose not mean modern day witches don't use brooms (we call them Bessoms) as part of some of our Rituals. The Bessom is used to ritually cleanse the area we use for our Circle (Sacred space) and as a common part of Hand-fasting Rituals (weddings).
The number 100 in Spanish is "ciento."
Witches is "brujas" in Spanish. Pronounced BRU-hahs. Singular is "bruja". The witch is "la bruja".
Cien.
Cien
Veinte/cien
To find ratings on electric brooms you could search online for stores that sell it and see what their customers had to say about it.
100hundredcenturycien (Spanish)cento (Italian)bai (Chinese)
cien años
un centenar de verdades
Noche de brujas (the night of the witches) or Halloween, it doesn't translate exactly and most hispanic countries do not celebrate it, but instead (El) día de muertos, which is different from Halloween.
el ano 100 (ciento) ano de cristo (I think)