การลบและการหาตัวเลขที่หายไป แผ่นงาน

Start with a concrete story: “I had 9 counters, some were removed, and 4 remain.” Have students model the situation, write 9 − □ = 4, and use addition to work backward. Rotate the unknown among the minuend, subtrahend, and difference so students learn to reason about the whole equation.

Use a mix of number-bond models, fact-family problems, equations with the blank in different positions, and short word problems. Include prompts such as □ − 3 = 5 and 8 − □ = 2; the second type requires different reasoning than simply calculating a difference.

Students often subtract the two visible numbers regardless of the blank’s position. They may also confuse the minuend with the subtrahend or assume subtraction is commutative. Ask students to substitute their answer into the original equation and check whether both sides are equal.

Host a worksheet as a digital quiz on Wayground, or download the printable PDF for paper practice. Paper submissions can be scanned or captured for grading with the Wayground for Teachers app, and every worksheet includes a complete answer key.

Common Core develops this work from understanding subtraction as taking apart or finding an unknown part, toward using the relationship between addition and subtraction to solve equations with an unknown in any position. That progression prepares students to treat the blank as a quantity to determine rather than as a signal to perform a memorized step.

For students who need less visual strain, create a version with larger type or wider spacing. A dyslexia-friendly font can make equations easier to track, while advanced learners can work with larger numbers or blanks placed in the minuend and subtrahend positions.