You've already learned how to use coins to better understand multiplication and division problems. Now we'll concentrate on writing number families for multiplication and division senten
You've already learned how to use coins to better understand multiplication and division problems. Now we'll concentrate on writing number families for multiplication and division sentences.
How do we write number families for sentences? We write two variables (letters) and a number. How do we know the lesser (smaller) number? Don't forget that the word after "each" is a lesser number.
Read this sentence: Each nickel is worth 5 cents.
What's the word following "each"? It's "nickel," so nickel is one of the lesser numbers. How much is each nickel worth? It's 5 cents, so 5 is the other lesser number. What's the greater (larger) number? It's how many cents we have in all. The number family for this coin problem looks like this:
Try a new number family for this sentence: Each quarter is worth 25 cents.
"Quarter" follows the word "each." Quarter is one of the lesser numbers. The cents for each quarter is the other lesser number. That's 25. The greater number is C.
Now let's try solving coin multiplication and division problems using nickels. Let's start with a multiplication problem:
Write 5 as the first lesser number because each nickel is worth 5 cents. Use 4 for N because you have 4 nickels. The multiplication problem you'll work to figure out the number of cents you have is 5 times 4 (5 × 4). The answer equals 20 cents.
Here's a coin division problem:
Write 5 for the first lesser number. Write 65, the total number of cents, as your greater number. When you divide 65 by 5 to get your other lesser number, you get 13 (65 ÷ 5 = 13). You have 13 nickels.
