I think one math word that starts with B might be 'bisection'. It's not always used in math, but frequently is.
agreeagreementegretogle
Entropy is a synonym for chaos. It begins with the letter e.
How about Greece, as in the country.
automobile
endorphins
# duels # duets
Exponents, equals
· eggplant
Some math words beginning with the letter E are:EqualsEquationEquilateralEvaluateExpandExpression
Aisle
Elbow, Ear, Eye...
lake Eire or however you spell it.
exponent
minte pie nshajshskuad
equation
Beetle is a 6 letter word that has 'e' as the third letter.
· Easter Lamb Cake · Éclair · Eggnog Ice Cream