Number Operations (Addition, Subtraction, Multiplication and Division)

E.g. 1 Use strategies studied in B1 and B2 (counting up, counting down, making doubles, making doubles plus or minus 1 or 2, making 10s, rearranging order of additions to make friendlier combinations, converting a subtraction into an addition and solving the addition) to demonstrate mastery of basic addition facts to 18 (and related subtraction facts)
E.g.2 Make doubles when both numbers are close to doubles or when one number is close to the double of the other by:
- decomposing one of the numbers to create doubles (e.g. when adding 25 + 26, think 25 + 25 + 1) or
- shifting a quantity from one number to the other to create doubles (e.g., when adding 24 + 26, think 25 + 25, or when adding 69 + 23, think 70 + 22)
E.g. 3 Make 10s when one number is close to 10 or to multiples of 10 by shifting a quantity from one number to the other to create a multiple of 10 (e.g. for example, instead of 28 + 47, think 30 + 45, which is the equivalent of moving 2 from 47 to 28 or think 25 + 50, which is the equivalent of moving 3 from 28 to 45)
E.g.4 Decomposing or partitioning the second number to create numbers that are easier to add and adding on in "friendly jumps" (e.g., when adding 36 + 35, start with 36, add 10 three times to get 66 (36 + 10 + 10 + 10), then add on 5 to get 71. The answer is 71.)

E.g. 5 Adding from left to right (adding 10s first and then ones) or using the splitting/partial sums strategy (e.g., to add 52 + 34, think 50 + 30 and 2 + 4
B3.1.2.3. Use strategies to mentally add and subtract whole numbers within 100
E.g. 1 Look for doubles, and then changing the subtraction question into an addition and solving it (e.g. for 24 - 12, think 12 + 12 = 24 so 24 - 12 is 12 )
E.g. 2 Make doubles when the two numbers that are close together or close to doubles by:
- Decomposing the second number to make doubles (e.g. when subtracting 48 - 25, think 48 - 24 - 1) or
- Compensating to make doubles: adding something to the second number to make a double, then adjusting the answer by adding the same amount to the answer (e.g. for 48 - 23 think 48 - 24 = 24. Then add 1 to 24 to get 25, which i E.g. 3 is the answer)
E.g. 3 Making 10s when the 2nd number is to 10 or to a multiple of 10 by compensation (i.e., adding something to the number, then adjusting the answer by adding the same amount to the answer e.g. for 48 - 19, subtract: 48 - 20 which is 18, then add 1 to that answer to get 19).
E.g. 4 Subtracting by counting up in friendly jumps. Start at 2nd number and jump up by friendly jumps to get to the first number and add up all the friendly jumps made (e.g.,71-36, start with 36 and make friendly jumps until you get to 71, for example 36 + 10 + 10 + 10 + 5 gives 71. The jumps made were 10 + 10 + 10 + 5, or 35 places in total. So the difference between 71 and 36 is 35) Printed pages 50 and 51 are transposed in this document. Printed p.51 continues this indicator (E.g. 4, E.g. 5, then a repeat of the indicator heading printed as "B3.1.2.3." with subtraction strategies E.g. 1 and E.g. 2) and printed p.50 carries E.g. 3 and E.g. 4 of that second block before content standard B3.1.2.4 begins. The exemplars are transcribed here in that reading order rather than in page order, and the repeated heading is kept in place. Printed p.51 also contains the typesetting error "which i E.g. 3 is the answer", transcribed as printed.