The calculator and powers of seven (5th grade math)
In this example, we find which exact power of seven is more than one million, using a calculator. This is a simple exercise helping students to learn to use the calculator.
Once you punch 7 × 7 = with a calculator, and get 49, you can just keep pushing the equals button, which will multiply your previous result by 7. And thus, you can get a sequence of numbers that are powers of 7: 7 to the third power (or 73, 7 to the fourth power (or 74), 7 to the fifth power (exponent is 5) and so on.
See also
The connection between multiplication and division, simple equations, bar models, terminology
More problem solving with bar models, part 1
Math Mammoth Grade 5 curriculum