Saxon Math Grade 1, Section 5: Time Measurement & Two-Digit Operations
In this unit, first graders tell time to the hour and half hour, compare and order lengths, and add two-digit numbers using tens and ones. They see the hour hand and the minute hand doing different jobs and make a new ten when the ones add up to 10 or more. It follows the shapes and equal parts of the last unit and closes the year.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Section 5?
- Adding a two-digit number and a one-digit number or a ten, like 27 + 6 or 27 + 40, using tens and ones. Learn more: Adding two-digit numbers within 100
- Ordering three objects from shortest to longest and using a string to compare lengths that can't be lined up. Learn more: Ordering three things from shortest to longest
- Reading and writing times on the hour and half hour, like 9:00 and 9:30, on both kinds of clocks. Learn more: Telling time to the hour and half hour
Sample questions to try together
These are real questions from our practice. Tap the speaker to hear one read aloud, or the light bulb for a hint, and talk about the answer together.
Question 1 of 3
If you have 2 tens and 4 ones, and then you get 5 more ones, how many do you have in total?
- 30
- 29
- 28
How you can help
- Read the clock together at the hour and half hour, like at lunch or bath time, and ask your child to write the time on paper.
- Line up three belts, scarves, or ribbons from shortest to longest, starting each from the same edge. Ask which one is in the middle.
- Add small prices at the store, like 27 cents plus 6 cents, and ask your child to make a ten from the ones.
Where kids can get stuck
- Writing 213 for 27 + 6 instead of making a new ten from the ones.
- Reading 9:30 as 10:30 because the short hand is near the 10.
- Comparing ribbons without lining up one end, so the shorter one looks longer.
Practice makes perfect
Bobby's Math Club has practice problems that adapt to your child’s level, each with a detailed explanation and an easy-to-follow video, so your child can build confidence in these skills one step at a time.
Words your child will hear
- tens
- Groups of ten. In 34, there are 3 tens.
- ones
- Single things not in a group of ten. In 34, there are 4 ones.
- sum
- The answer when you add, like 7 in 3 + 4 = 7.
- length
- How long something is from one end to the other.
- compare
- Look at two things to see which is bigger, longer, or the same.
- hour hand
- The short hand on a clock; it shows the hour.
- minute hand
- The long hand on a clock; it shows the minutes.
- half past
- Thirty minutes after the hour, like 3:30.
Want to help your child master time and two-digit adding?
In Bobby's Math Club, your child practices these skills at just the right level, with a hint when they need one, a clear explanation after every question, and kid-friendly videos. Unlimited practice is free.
Join the club
Written by Robert “Bobby” Barnett
Bobby is an award-winning math teacher, the author of Meet Every Learner’s Needs, and the father of two elementary-school math learners. He uses Bobby’s Math Club with his own kids a few times every week. Learn more or contact Bobby.
Which math standards does Saxon Math Grade 1 Section 5 cover?
Saxon Math Grade 1 Section 5 covers these math standards. Each one links to what it means, sample questions, and teaching strategies.
For teachers: Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence. Learn how Bobby's Math Club can help your students grow.