Subtraction is one of the four arithmetic operations along with addition, multiplication, and division. It is an essential tool to help us calculate what is left when taking one number away from another. The exercise below can be used to teach subtraction to children. Copyright 2024: Edublox (Pty) Ltd.
Materials required:
• Blocks or buttons of the same color inside a box.
• A paper plate or shallow container.
• Subtracting flashcards (see PDF file below).
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Description:
The tutor shows the learner the first subtracting card, 1 – 1, and asks, “What does the card say?” The learner must answer, “One minus one.” The tutor then tells the learner, “Take the blocks and show me what one minus one looks like when blocks are used.”
The learner must remove one block from the box, put it on the plate, and then put the block back into the box.
The tutor asks, “What is the answer?” to which the learner must answer, “Zero.”
The tutor shows the learner the next subtracting card, 1 – 0, and asks, “What does the card say?” The learner must answer, “One minus zero.” The tutor will ask the learner, “Take the blocks and show me what one minus zero looks like when blocks are used.”
The learner must remove one block from the box and keep it on the plate.
The tutor shows the learner the next subtracting card, 2 – 2, and asks, “What does the card say?” The learner must answer, “Two minus two.” The tutor will ask the learner, “Take the blocks and show me what two minus two looks like when blocks are used.”
The learners must remove two blocks from the box, put them on the plate, and then put the two blocks back into the box.
If the learner gives an incorrect answer, the tutor will help the learner get to the correct answer through leading questions.
The tutor will continue this way until she has the first six subtracting cards in her hand.
The tutor shuffles the six cards, puts the first one down on the table, and immediately covers it with her hand. The action of putting the flashcard on the table and covering it with one’s hand must be quick.
With her hand covering the flashcard, the tutor waits for the learner to say the answer.
She then puts the next card in front of him the same way and waits for him to answer, followed by the third, fourth, fifth, and sixth flashcards.
If the learner cannot give a correct answer, or if he gives an answer hesitantly, she must put the card(s) in question aside so that it (they) can be drilled later. To drill, she puts the flashcard(s) (one at a time) in front of the learner and asks, “What is the answer?” She drills it (them) over and over until he can say the answer(s) fluently. If needed, the learner can again use blocks to illustrate an equation.
The six flashcards are shuffled, and the process is repeated.
If (or as soon as) the learner is able to say the answers to the six flashcards correctly and without hesitation, two more flashcards are added, and the process starts all over again:
1.) Two more subtracting cards are added
The tutor shows the learner the new subtracting card, 3 – 2, and asks, “What does the card say?” The learner must answer, “Three minus two.” The tutor will ask the learner, “Take the blocks and show me what three minus two looks like when blocks are used.”
The learner illustrates 3 – 2 with blocks, and the tutor asks, “What is the answer?” to which the learner must say, “One.” Etc.
2.) The tutor shuffles the eight cards, puts them down on the table, and immediately covers them with her hand.
If the learner cannot give a correct answer, or if he answers hesitantly, she must put the card(s) in question aside so that it (they) can be drilled later. To drill, she shows the subtracting card(s) (one at a time) to the learner and asks, “What is the answer?” She drills it (them) over and over until he can say the answer(s) fluently. If needed, the learner can again use blocks to illustrate an equation.
3.) Two are added if (or as soon as) the learner is able to answer the eight flashcards correctly and without hesitation.
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