One plus one -Royalty Free Image License: Standard LicenseStandard Royalty Free License One plus one mathematical formula written on chalkboard 298 views Ray Woo An experience stock photographer based in China. The main topics of my works... [more] info Author Page Portfolio: 3124 images. Updates / RSS Network Image updated—August 25, 2013 Keywords add, answer, arithmetic, beginner, black, blackboard, board, calculate, chalk drawing, chalkboard, class, concept, education, elementary, equal, equation, exam, examination, formula, handwriting, learn, lesson, letter, mark, math, mathematical, mathematics, number, numeral, numeric, one, plus, preschool, problem, question, school, script, sign, symbol, teach, text, word, write, writing Image Categories Blackboard | Concepts | Handwriting Image #4374 Size Type File Info Price ( US Dollars $ )50% off Bloggeejpg6.94" × 4.63" @ 72 dpi500 × 333px2.001.00 Smalljpg13.89" × 9.24" @ 72 dpi1000 × 665px4.002.00 Mediumjpg8.33" × 5.55" @ 300 dpi2500 × 1664px8.004.00 Largejpg14.19" × 9.44" @ 300 dpi4256 × 2832px12.006.00 End User License Agreement View Cart (0.00) Symbiostock Community Symbiostock CommunityNetwork with illustrators, photographers, and designers. Symbiostock on TwitterSymbiostock news. Symbiostock on FacebookCommunity maintained Facebook hub. Symbiostock.infoSearch images on the Symbiostock network. Symbiostock SearchSearch Symbiostock images and network. Symbioguides.comSymbiostock knowledge base. Symbiostock.comSell your images and network with fellow microstock professionals. ClipArtof.comHigh Resolution Stock Illustrations & Clip Art ClipArtIllustration.comFirst Symbiostock Site, and home of the Orange Man Microstockgroup.comA meeting place for microstock professionals.