express 21÷5 as a decimal

Question

Please help me harddddd:-X:'(:'(:'(

Answer 1

There's an easy way to do this because we know that 2*5=10. We multiply 21 by 2 rather than divide by 5. We get 42. But we move the decimal point one place to the left (it sits invisibly after 42) giving us: 4.2. Yes, that's the answer. We know that 20 divided by 5 is 4, and 4.2 is a little bigger than 4, as we'd expect.