1.NBT.6
Subtract multiples of 10 in the range 10-90 from multiples of 10 in the range 10-90 (positive or zero differences), using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used.
| 1. | Which number is 10 less than 30? | |
| 2. | Which number is 10 less than 20? | |
| 3. | Which number is 10 less than 10? | |
| 4. | Which number is 10 less than 50? | |
| 5. | Which number is 10 less than 40? | |
| 6. | Which number is 10 less than 80? | |
| 7. | Which number is 10 less than 60? | |
| 8. | Which number is 10 less than 90? | |
| 9. | Which number is 10 less than 70? |