Heather is making a road with red blocks and blue blocks. She needs 52 blocks altogether.
Which group of red and blue blocks will make 52?
Eric and Dana are making a bridge out of blocks. They choose 23 green blocks and 30 red blocks. How many blocks do they use altogether?
What is the missing number?
Which number is missing?
All the robots have been working hard to make new numbers. Which multiple of 10 have they added?