Intellijoy is your go-to source for Common Core Math apps. As our premier math app, First Grade Math Word Problems is the first of many which will hit the market. Easy-to-use exercises for First Grade Math Word Problems. Number sums up to 20. 5 categories including 50 word sentences (this Lite version has only the 1st and the 3rd categories) : Addition using same elements - Addition using different elements- Subtraction using same elements- Subtraction using different elements- Comparison- using addition or subtraction. Children enjoy reading or listening to simple sentences which provide real-life scenarios to reinforce the child's understanding of addition and subtraction.