Fill in the missing numbers by starting at 19 and counting backward two each time.
Michael holds up 9 fingers and starts counting down as he puts down one finger at a time. He stops when he is holding up 4 fingers.
Decide whether he was adding or subtracting by picking the number sentence that describes what he did.
Isabella put her counter on 12 then moved it back 2 spaces.
Help her find the missing number:
This machine subtracts 3 from any number. What numbers are missing?
On this domino, the dots on one side are covered with a sticker, and the total number of dots is written above it.
How many dots are under the sticker on this domino?