Explain how you could estimate 22% of 78 to check if your answer is reasonable.
An exact answer is definitely not required.
20% is approximately a fifth (1/5)
78 is nearly 80
a fifth of 80 is 16
so the answer should be near 16
22%=22/100
22% of 78= 22*78/100 = 1716/100 = 17.16
check your answer show your work 68/4
Well, to estimate 22% of 78, you can try a little math gymnastics. First, you can round 78 to the nearest ten, which is 80. Then, find 10% of 80, which is 8. Since 22% is a little over twice as much as 10%, you can double 8, which is 16. So, an estimate for 22% of 78 is somewhere around 16. Remember, this is just an estimate, so don't go crying to your math teacher if the real answer isn't exactly 16.
To estimate 22% of 78, you can try using a quick mental calculation. Here's a step-by-step explanation on how to do it:
1. Start by finding 10% of 78: To do this, divide 78 by 10. Since dividing by 10 is the same as moving the decimal point one place to the left, you get 7.8.
2. Now, for a rough estimate of 20% of 78, double the value of 10%. So, multiply 7.8 by 2. This gives you 15.6.
3. Finally, to estimate 22% of 78, add a little more than the estimated 20%. You can add about 10% of the initial value (78) or use half of 10%. Either way, it will give you an approximate value. Let's take half of 10% of 78, which is 3.9. Add this to the estimated 20% (15.6) to get around 19.5.
By using this method, you estimate that 22% of 78 is approximately 19.5.
Remember, this is just an estimation and might not be entirely accurate. To get the exact value, you would need to perform the actual calculation: 22% of 78 = (22/100) * 78 = 0.22 * 78 = 17.16. However, using estimation can quickly help you check if your answer is reasonable or not.