Grade 2 • Mathematics • Number Operations

Grade 2 Mathematics

Number Operations

Number Operations Vocabulary

• Addition: to join two or more groups (Example: 2 + 3 = 5)
• Subtraction: to find the difference when two groups are compared or to find out how many are left when items are taken away from a group
• Addend: a number that is added to another in an addition problem (Example: in 2 + 3 = 5, 2 and 3 are addends)
• Difference: The answer to a subtraction problem (Example: in 8 – 3 = 5, 5 is the difference)
• Sum: The answer to an addition problem (Example: in 2 + 3 = 5, 5 is the sum)
• Equal Sign (=): a symbol used to show that two amounts have the same value (Example: 384 = 384)
• Number Sentence: includes numbers, operation symbols ( +,- ), and a greater than or less than symbol ( >,< ) or equal sign (Example: 5 + 3 = 8, 25 < 32)
• Regroup: to exchange amounts of equal value to rename a number
• Decompose: to break a number into smaller parts to simplify computation (Example: 15 = 10 + 5)
• Compose: to put decomposed numbers back together (Example: 10 + 5 = 15)
• Array: an arrangement that shows objects in rows and columns

Number Operations Activities 

• Roll single-digit numbers and add them together.
• Roll 2-digit or 3-digit numbers and add them together.
• Roll two dice to make a two-digit number. Subtract it from 99 or 100.
• Add all the digits of your house number together.
• Make a train with Legos or colored blocks. Write a number sentence for the different colors in the train.
• Represent two digit numbers with popsicle sticks – make bundles of ten for the tens and use single sticks for the ones. Add the piles together.
• Use small items (counters, beans, small toys) to represent number sentences. Use index cards to make +, -, <, >, and = symbols. Show a number sentence with a missing element: 7 + ___ = 12. Have your student find the missing addend.
• Add the price of two items at a store.
• Compare gas prices to find the lowest amount.
• Roll a 2-digit number and subtract it from 99 or 100.
• Start with 100 counters (beans, pennies, etc.) and roll two dice to make a 2-digit number. Subtract counters until you get to 0.
• Give your student an addition or subtraction number sentence and ask them to make up a story problem to go with the number sentence.
• Look for items that are in repeated sets or groups – panes in a window, pickets on a fence, sodas in a six-pack, wheels on cars or bicycles.
• Make a physical array with counters and record on paper using symbols.

Number Operations Independent Practice

• Sums and Differences on a Number Line Links to an external site.
• Solving One- and Two-Step Word Problems Links to an external site.
• Odd and Even Links to an external site.
• Add and Subtract Within 100 Links to an external site.
• Add and Subtract Within 1000 Links to an external site.