LearnWave
Learn it. Master it.

Another Peek Beyond the Point

Is the product always bigger?

Find out whether multiplying by a decimal always makes a number bigger.

With fractions you saw that the product is not always greater than the numbers multiplied. Decimals are just another way of writing fractions, so the same thing happens — and it is worth checking with decimal examples.

Take 2.25 × 8 = 18. The product, 18, is greater than 2.25 and greater than 8. That is the familiar case.

Now 0.25 × 8 = 2. The product is greater than 0.25, but LESS than 8. It has landed between the two numbers.

And 0.25 × 0.8 = 0.2. Now the product is less than 0.25 AND less than 0.8 — smaller than both.

So when is the product greater than both, and when less? It depends, exactly as with fractions, on whether each number is between 0 and 1 or greater than 1.

Situation 1: both numbers greater than 1, as in 3.4 × 6.5 = 22.1. The product is greater than both. Situation 2: both between 0 and 1, as in 0.75 × 0.4 = 0.3. The product is less than both.

Situation 3: one between 0 and 1 and one greater than 1, as in 0.75 × 5 = 3.75. The product is less than the number greater than 1, and greater than the number between 0 and 1 — it lands between them. The short version is the same as before: multiplying by something less than 1 shrinks, and multiplying by something more than 1 grows.

Times a number less than 1 makes things smaller; times a number more than 1 makes them bigger.

Practise this lesson

Questions that get harder as you improve, a Tutor that helps without giving the answer away, and progress you can see. Free for every learner.

No account, no email address. Opens the real product.