In this app subtraction is illustrated by taking away numbers of objects. If, for instance, the subtraction problem (which appears at the top of the screen) is 8 - 2 = ? the student will be told to click on the blinking number 8. Eight apples will rise from the group at the bottom of the screen to the space under the 8. Now the second number (2) will be blinking and the student will be told to click on the blinking number. Two apples from among the eight at the top of the screen (the last two) will be numbered 1 and 2, and they will start to blink. The program voice will tell the student to “Click the blinking apples one by one.” When each numbered blinking apple is clicked, it will descend into a basket on the bottom right hand side of the screen. The remaining apples at the top of the screen under the 8 will start to blink one by
one, and the student will count these remaining apples by clicking on each one. (As the student clicks on each apple it will change from a red apple to a green apple and get a number) After all the apples are green and numbered, the screen voice will tell the student to click on the last numbered apple (6). The answer (6) will rise into the answer space. The program voice will say “Yes eight minus two is 6.” This program uses only numbers from 1 to 10.
If this is selected, then any and all of the numbers in this box will be used. To deselect this choice, click it again and selection will be ended.
Select Random Numbers
If this is selected, then the program will choose the numbers to be used in the problems.
This box is checked by default. When this is checked, clicking the correct number invites a congratulatory animation. This animation runs for ten seconds. Click anywhere on the screen or press the space bar to stop the congratulatory animation.
Click on the “Back” button to close “Subtraction by Taking Away Objects” or return to the previous page.