Learn to compare decimal values and see how they work in the world of money.
If someone offered you of a chocolate bar or of the same bar, which would you choose? They both have a '7,' but one will leave you much hungrier than the other!
To compare decimals, we must look at the place value of each digit. The first spot to the right of the decimal point is the tenths place. The second spot is the hundredths place. Think of the decimal point as a wall. The closer a digit is to that wall (on the right), the bigger its value! A in the tenths place () means you have 7 out of 10 equal parts. A in the hundredths place () means you only have 7 out of 100 equal parts. It is like comparing 7 giant slices of pizza to 7 tiny crumbs!
Compare and . 1. Line up the decimal points: 2. Add a placeholder zero to so they have the same number of digits: and . 3. Compare the numbers: is greater than . 4. Therefore, .
Quick Check
Which number is larger: or ?
Answer
is larger because it is the same as , and hundredths is more than hundredths.
One of the easiest ways to compare decimals is to think about money. The tenths place represents dimes, and the hundredths place represents pennies. Since it takes 10 dimes to make a dollar, one dime is or . Since it takes 100 pennies to make a dollar, one penny is . If you are comparing and , just think: 'Would I rather have 3 dimes ( cents) or 25 pennies ( cents)?' The dimes win every time!
You have two coupons for a toy. Coupon A is for off the price. Coupon B is for off. Which saves you more? 1. Convert to money: becomes (60 cents). 2. Compare to Coupon B: (59 cents). 3. . 4. Coupon A saves you more money!
Quick Check
Is the same amount of money as ?
Answer
Yes, both represent 40 cents (or 4 dimes).
When we use a 100-grid (a square broken into 100 small boxes), we can see the difference clearly. To model , you would color in 7 full columns (70 small squares). To model , you would color in only 7 tiny individual squares. The visual area covered by is much larger than . This proves that even though they both use the digit 7, their position changes everything.
Three snails had a race. Snail A traveled meters, Snail B traveled meters, and Snail C traveled meters. Who came in first, second, and third? 1. Give them all two decimal places: . 2. Compare the values: . 3. 1st Place: Snail B (m), 2nd Place: Snail A (m), 3rd Place: Snail C (m).
Which symbol correctly compares the two decimals? ____
Which is the largest value?
is greater than because is greater than .
Review Tomorrow
In 24 hours, try to explain to a friend why is bigger than using the 'dimes and pennies' rule.
Practice Activity
Next time you are at the store, look at the prices of two items. Identify which digit is in the tenths place and which is in the hundredths place for both!