Idea 1of 23
Tenths: one whole cut into 10
What does the first digit after a decimal point count?
Today you'll discover
- what one tenth of a whole looks like
- how to write 3 tenths as a decimal
- why 0.3 and 3/10 are the same
Think firstOne whole square, cut into 10 equal strips
The square is 1 whole. What is one strip of it worth?
Decide first, then press Next. Count the strips, and keep the whole square in mind.
A large square marked 1 whole, cut by upright lines into 10 equal strips. Then 3 strips are shaded, with the words 3 tenths, and the decimal 0.3 is written beside it, then = 3/10. The last step shows 7 strips shaded.
See the whole ideathe big idea and the key word, in one place
The big idea
The first place after the decimal point counts tenths: one whole cut into 10 equal parts.
Three ways to say it
3 strips out of 10 equal strips is 3 tenths, 3/10 or 0.3. All three name the same amount.
- In words3 tenths
- Fraction3/10
- Decimal0.3
Easy to get wrongThe parts must be equal. 10 strips of different widths would not be tenths.
Key words
- tenth
- one of 10 equal parts of a whole, written 0.1 or 1/10
- decimal point
- the dot that sits just right of the ones place; the places after it are parts of a whole
Ready to use it?
- Write the shaded part of a whole as a decimal.
- Place a tenth on a number line.