This driller challenges all ages from kids to adults. The the difficulty level and the time limit for a session is set with Level tab as shown in the Figure 1.
Figure 1
The difficulty level corresponds to the selected the range (0 to 9, 0 to 49, and 0 to 99) of numbers. Advanced users, select decimal numbers and signed operations. The time limit for a set of 15 problems must be set to challenge the user (60 seconds is the default).
The next step is to select the operation to be practiced. The operations addition (+), subtraction (-), multiplication (X) and division (/) are supported. To practice either addition or subtraction operation, first click the "+ and -" tab and the available options are shown as in Figure 2.
Figure 2
Similarly, one can select "x and /" tab to practice either the multiplication or the division operation, or both. First select the operation as desired and then select the divisor or the multiplier.
Figure 3
Suppose 15 is selected as a multiplier. The driller now presents multiplication problems with multiplier up to 15. This applies to division operation too.