During Unit 2, your child will extend their understanding of the base-ten system to the relationship between adjacent places, how numbers compare, and how numbers round for decimals to thousandths.
Students need to:
- Recognize that in a multi-digit number, a digit in one place represents 10 times as much as it represents in the place to its right and 1/10 of what it represents in the place to its left.
- Explain patterns in the number of zeros of the product when multiplying a number by powers of 10, and explain patterns in the placement of the decimal point when a decimal is multiplied or divided by a power of 10. Use whole-number exponents to denote powers of 10.
- Read, write, and compare decimals to thousandths.
- Read and write decimals to thousandths using base-ten numerals, number names, and expanded form, e.g., 347.392 = 3 × 100 + 4 × 10 + 7 × 1 + 3 × (1/10) + 9 × (1/100) + 2 × (1/1000).
- Compare two decimals to thousandths based on meanings of the digits in each place, using >, =, and < symbols to record the results of comparisons.
- Use place value understanding to round decimals to any place.
- Add, subtract, multiply, and divide decimals to hundredths, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used.
- Convert among different-sized standard measurement units within a given measurement system (e.g., convert 5 cm to 0.05 m), and use these conversions in solving multi-step real world problems.
- Use parentheses, brackets, or braces in numerical expressions, and evaluate expressions with these symbols.
Carroll County Public Schools Video Support
Using the Powers of 10
Multiplying a Whole Numbers by a Decimal
Multiply Decimals with Models and Open Arrays
Ways Parents Can Help
- Play "wipe-out" with a calculator. Students key in the same number, for ex. 256,734.891. Ask them to "wipeout" one of the digits without changing any of the other digits. Ex. "Wipe out the digit 9." Students will need to know that the 9 has a value of 0.09 in order to wipe it out from the calculator.
- How many articles/items can you find in a catalog with prices that have a given number in the units place and a given number in the tenths place and or the hundredths place? (i.e. with a 3 in the units place, a 7 in the tenths place and a nine in the hundredths place)
- Play 20 questions using a number as what needs to be figured out using questions focusing on place value.
- Compare decimals that they see in their environment (i.e. cost of items, times at a sporting event, weight on a digital scale…
Some Support Sites