Two-digit numbers
Japanese school year: Elementary 2
What you learn
Students learn to add and subtract two-digit numbers by aligning tens and ones places. These calculation skills are widely used in daily situations, such as finding total prices or change. Being confident with single-digit addition and subtraction involving regrouping will help you master this unit quickly.
Key points
When adding or subtracting two-digit numbers, calculate the ones together and the tens together.
When the ones digits add up to 10 or more, carry 1 over to the tens place.
If you cannot subtract the ones digit, borrow 1 ten from the tens place.
Choose a set to practice.