Count on to add
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Count on to add: skill guide
| Objective | Learners add a one-digit number to a two-digit number by counting on. |
|---|---|
| Grade | Grade 1 |
| Standard | CCSS.MATH.CONTENT.1.OA.C.5 |
| Difficulty | Developing · Abstract |
| Representation | Number sequence, Numerical equation |
| Practice format | Interactive, account-free practice with immediate feedback |
Objective
Learners add a one-digit number to a two-digit number by counting on.
What this practice covers
Each problem is an addition equation such as 47 + 5 = □, written with numerals only. The first number is from 21 to 89 and the second is from 2 to 9. The learner finds the total by counting on from the first number and chooses it from five nearby numbers. Some totals cross into the next ten, as in 47 + 5 = 52.
Standards alignment
Supports Common Core: CCSS.MATH.CONTENT.1.OA.C.5 — Relate counting to addition and subtraction.
Who it’s for
This practice is designed for Grade 1 learners adding within 100. It is also useful for older learners who want a short review of adding a one-digit number to a two-digit number.
What to know first
- Learners should count reliably to 100, read two-digit numerals, and understand addition as joining parts.
Difficulty and scaffolding
Developing · Abstract stage
Problem representations
- Number sequence
- Numerical equation
Three worked examples
- 34 + 3 = 37: start at 34 and count on 35, 36, 37.
- 56 + 7 = 63: count on 7 from 56 to 57, 58, 59, 60, 61, 62, 63.
- 68 + 5 = 73: 2 more makes 70, then 3 more makes 73.
Likely misconceptions
- Learners may say the first number as their first count, as in 34, 35, 36 for 34 + 3, or keep the same tens digit after passing a ten, as in 56 + 7 = 53. Start counting with the number after the first, and check whether the count passed a multiple of ten.
Hints and explanations
- 34 + 3 = 37: start at 34 and count on 35, 36, 37.
- 56 + 7 = 63: count on 7 from 56 to 57, 58, 59, 60, 61, 62, 63.
- 68 + 5 = 73: 2 more makes 70, then 3 more makes 73.
What to practice next
Next, move to subtraction and take 4 to 9 away from a number between 11 and 19.
Editorial review
Reviewed by Brilliant’s curriculum team. Exercises are generated within defined difficulty ranges and checked against verified answer rules.
Count on to add FAQs
What is the goal of count on to add?
The goal is to add a one-digit number to a two-digit number by counting on. A learner should be able to explain where the count started and how many numbers were counted.
Should this practice be timed?
No timer is required. First build accurate, understandable strategies. Speed usually improves naturally as learners recognize groups of ten, familiar facts, and repeated patterns.
What should a learner do after a mistake?
Count on again from the first number, raising one finger for each number added, and say where the count ends. A short explanation is more valuable than immediately repeating the same guess.
How many problems should be completed at once?
A Quick check has 5 problems and a Practice session has 15. A learner may pause when attention drops. A short, successful session with clear reasoning is more useful than rushing through a longer set.