Adding Tens

The process is: 

• Say, ‘My turn to plus tens. I’ll start with 21 and ten to 51. What number will I start with?’ and signal. 
• Ask, ‘What number will I plus tens to?’ and signal. 
• Say, ‘Here I go: 21, 31, 41, 51’. 
• Say, ‘Your turn: Start with 21 and tens to 51′. 
• Say, ‘Get 21 going’ and signal. Say, ‘Plus tens’ and signal – ‘tap 3’. 
• Repeat the steps for additional series. 

This counting technique is important for CMC B-level students because they later will apply it when they add ten to two-digit and three-digit numbers.