Find one missing addend in each addition equation. The ten-question round builds from easy facts to crossing ten.
Missing Number Addition within 20
Your Missing Number round
Ten questions with immediate feedback, alternating the blank between the addends.
Missing Number Addition within 20Question 1 / 10
0 / 10
Find the missing number and enter it directly in the equation.
+2=4
Enter the missing number.
Round complete.
Correct first time: 0 / 10
This web round is not saved.
Think about what joins the known part
Read the whole equation before you answer. If the first addend is missing, ask what must join the second addend to make the total. If the second addend is missing, begin with the first addend and count on to the total.
The blank alternates between the left and right addend. Every total stays within 20, zero is not used, and no answer is revealed after an incorrect attempt.
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