It took an earthquake to convince one city to do away with a double-decker highway. City planners in San Francisco had tried for years to get approval for removing the Embarcadero Freeway that blocked ...

Represent teen numbers with addition and subtraction equations involving one 10. Represent 10 using a number bond and 10-frame with a missing addend. Use Notice and Wonder with a 10-frame, connecting ...

When you subtract using large numbers, it's often better to use a written method. Column subtraction is a good written method to take one number away from another. It involves writing the smaller ...

Practice adding and subtracting within 20 using a Double 10-frame & number line. Represent a teen number using a number bond to solve a Mystery Math Mistake. Use Notice and Wonder with a marble game ...