Find all the prime numbers between 40 and 60.

A square has a perimeter of 36 cm. Find the length of one side and its area.

Estimate the following by rounding off each number to the nearest 1000:

(a) 8,756 + 5,234

(b) 12,845 - 6,379

Also write the actual answers and compare them with the estimates.

Using a number line, solve (-8) + (-4) + 6. Verify the associative identity of addition for integers -8, -4 and 6.