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 ...

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 ...

You can subtract in Excel by placing a minus sign in front of any numbers you want to deduct. You can add and subtract a bunch of numbers at once using the equal sign or SUM function. You can add and ...