Addition, subtraction, multiplication, & division
Understand what it means to multiply numbers – for example: 5 x 3 can be thought of as the total number of objects in three groups where each group contains five objects – or the total number of objects in five groups where each group contains three objects. Relate the concept of addition to multiplication.
Know the times table. By the end of third grade, quickly and accurately multiply any one-digit number by any other one-digit number.
Time spent commuting or waiting in a car is a great opportunity to play math games with your child. Multiplication is one of the key math concepts she is working on in school and you can help her practice by asking her simple multiplication problems that relate to real life. Ask her to figure out the number of days until an event three weeks from today. Or have her calculate how many weeks she would have to save her allowance to buy a toy or game she wants.
Multiplication and addition
Use knowledge of addition to understand that 4 x 7 is the same as 4 x 5 + 4 x 2.
Understand that dividing numbers can be looked at as separating numbers of objects into equal groups.
Understand the relationship between multiplication and division. For example, understand that if 9 x 3 = 27, then 27 ÷ 9 = 3, and 27 ÷ 3 = 9.
Division with an unknown
Solve division problems involving an unknown – for example, solve 27 ÷ 9 = ? by thinking 9 x ? = 27.
Understanding place value
Use understanding of place value to add, subtract, multiply and divide multi-digit numbers.
Solving word problems
Solve word problems involving multiplication and division of numbers within 100.
The second-grade class and third-grade class were collecting old cell phones to recycle. The third grade class collected 10 old cell phones. The second grade class collected twice (two times) that number. How many cell phones did the second grade class collect?
The second-grade class decided to divide their collected cell phones equally between five different charities. How many phones will each charity get?
Fractions as numbers
Understand fractions as numbers. Using visual models or number lines (example below), understand that two fractions are equivalent (equal) if they are the same size, or are on the same point on a number line. For example, 2⁄4 is the same as 1⁄2.
Understand unit fractions – fractions with one as the numerator (top number): 1⁄2, 1⁄3, 1⁄4 – as one part of a whole when that whole is divided into equal parts.
Tip: Highlight real-life math problems
Continue to find as many opportunities as possible to highlight math problems in real life. If you’re doubling a recipe and need to figure out measurements, enlist your third-grader’s help. Measuring cups provide an especially good opportunity for your child to familiarize herself with the concept of fractions that they are leaning about in school. If a recipe calls for a cup and a half of something, ask them how many 1⁄2 or 1⁄4 cups they would need until they had enough.
Tip: Highlight real-life examples of fractions
Encourage your child to spot real-life uses of fractions, such as menus that describe burgers as quarter-pounders or sports games that are divided into halves. Have them practice fractions by drawing a shape, such as a circle or a square, and asking her to color in 1⁄2 or 3⁄4 of it.
Compare two fractions with the same numerator (top number) or the same denominator (bottom number) by thinking about their size, and what the top numbers and bottom numbers represent. For example, understand that 3/4 of something is larger than 3/5 of that same thing, because each fourth is larger than each fifth. Understand that 4/6 of something is larger than 3/6 of that same thing because it has four of the sixths.
Recognize that a fraction with the same numerator and denominator is the same as one – for example, 2⁄2 = 1 (two halves are the same as one whole). Write whole numbers as fractions – for example, 5⁄(1) is the same as five.
Read circular “face” clocks and digital clocks to tell time to the nearest minute. Solve word problems requiring addition and subtraction of intervals of time, in minutes. For example: Soccer practice is over at 4:15 p.m. Jose tells your child his mother will pick them up and drop your child off at home in 20 minutes. If they are on time, what time will it be when your child arrives?
Measurement & data
Mass and volume
Measure and estimate the mass of objects and volume of liquids – in grams (g), kilograms (kg), and liters (l).
Solve word problems involving mass and volume.
Brian has a mass of 85 kilograms. Joe is 9 kilograms lighter than Brian. What is Joe’s mass?
A mug has a volume of 540 milliliters. A cup has a volume of 230 milliliters. What is the total volume of the mug and the cup?
Data on graphs
Represent and interpret data on picture graphs and bar graphs (for example one square represents five pets). Solve one-and two- step word problems using information presented in bar graphs.
Use similarities and differences in geometric shapes to categorize, or classify them – for example, recognize that rectangles, squares, and rhombuses all have four sides, which makes them all examples of quadrilaterals (four-sided shapes).
Divide shapes into parts with equal sizes. Relate the parts to fractions of the whole.
TODAY's Parenting Guides resources were developed by NBC News Learn with the help of subject-matter experts, and align with the Common Core State Standards.