

For more practice,

The Wonder Number Lessons
Lesson No. 5: Subtracton, SingleDigit Subtraction is finding the difference between two numbers. The Wonder Number Board lets students discover the difference when this operation takes place. The first example of single digit subtraction is 7  3. Begin by counting out and placing seven blue chips on the numbers from 1 to 7 on the board. Explain that subtraction means taking one number away from another number to find the difference. Remove three chips, counting aloud one chip at a time, until you have four chips remaining (see fig 26). The student will discover the answer is 4. To selfcheck, lift up the last red chip and verify the answer. You can also verify your answer by counting the remaining chips on the board. The second example of single digit subtraction is 9  7. Begin by counting out and placing nine blue chips on the numbers from 1 to 9 on the board. Explain that subtraction means taking one number away from another number to find the difference. Remove seven chips, counting aloud one chip at a time, until you have two chips remaining (see fig 27). The student will discover the answer is 2. To selfcheck, lift up the last blue chip and verify the answer. You can also verify your answer by counting the remaining chips on the board. Another example of subtraction is 13  6. Begin by counting out and placing thirteen blue chips on the numbers from 1 to 13 on the board. Explain that subtraction means taking one number away from another number to find the difference. Remove six chips, counting aloud one chip at a time, until you have seven chips remaining (see fig 28). The student will discover the answer is 7. To selfcheck, lift up the last blue chip and verify the answer. You can also verify your answer by counting the remaining chips on the board.

