Adding Whole Tens, Missing Number — Grade 2
Practice finding missing numbers in whole tens addition problems. Free printable worksheets for second graders.
Missing number problems in whole tens addition help second graders understand the relationship between addition and subtraction. These worksheets focus on problems where students find an unknown addend, such as ___ + 80 = 110.
When teaching missing number problems, start with concrete manipulatives to show what's missing. Use base-10 blocks or place value charts to visualize the problem. Teach students to use subtraction to find the missing number, reinforcing the inverse relationship between addition and subtraction.
Adding Whole Tens, Missing Number Worksheets
Practice finding missing numbers in whole tens addition with visual support and answer keys.
Teaching Overview
When introducing missing number problems, begin with concrete examples. Use base-10 blocks to show a problem like ___ + 80 = 110. Show 8 tens blocks, then ask how many more tens are needed to make 11 tens (110). This concrete experience helps students understand what's missing.
Next, introduce the subtraction strategy. Show that if ___ + 80 = 110, then 110 - 80 = 30. Use number lines to visualize this: start at 80, jump to 110, and see that the jump is 30. Practice this repeatedly with different missing number problems.
As students become comfortable, encourage mental strategies. Teach them to recognize that finding a missing addend is the same as subtracting the known addend from the sum. For whole tens, this becomes simpler: if ___ + 80 = 110, think 11 tens - 8 tens = 3 tens = 30.
Finally, always encourage students to check their answers by adding the found number to the known addend. This self-checking habit builds confidence and reinforces the relationship between addition and subtraction.