Tropical cyclone scales barometric pressure is low compared with its surroundings. Other classifications historically used include: cyclonic storm where the winds did not exceed force 10 on the Beaufort scale and a Cyclone where the winds are either force 11 and 12 on the Beaufort scale. Between 1924 and 1988, tropical cyclones were classified into four categories: depression, deep depression, cyclonic storms and severe cyclonic storms. However, a change was made during 1988 to introduce the category "severe cyclonic storm with core of hurricane winds" for tropical cyclones, with wind speeds of more than . During 1999 the categories Very Severe Cyclonic Storm
Equate (game) integers imprinted on them, integer exponents, fractions, the four basic operations, and equal symbols. The additional tiles are sold separately, not with the board. Equate (game) Equate is a board game made by Conceptual Math Media where players score points by forming equations on a 19x19 game board. Equations appear across and down in a crossword fashion and must be mathematically correct. It is similar to "Scrabble" except players use digits and mathematical operators instead of letters. Equate can be beneficially used in both a classroom and as a board game for the family. To earn higher scores, a player